Vision . by | Baia 


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RADIO PICTURES 


Vision by Radio 
Radio Photographs 
Radio Photograms 


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C. FRANCIS JENKINS 


W ASHINGTON 


CopyrIGHTED, 1925, BY — 
JeNKrinS LABORATORIES, IN 
WasuinctTon, D. C. 


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{To the splendid young folks, Sybil 
L. Almand, Florence M. Anthony, 
John N. Ogle, James W. Robinson, 
Stuart W. Jenks, and Thornton P. 
Dewhirst, who so efficiently assisted 
in the attainment of Photographs by 
Radio, Radio Vision, and Radio Pho- 
tograms, this book, in grateful ap- 
preciation, is dedicated. 


Mr. C. Francis Jenkins 


Born in the country, north of Dayton, Ohio, in 
1868, of Quaker parents. Spent boyhood on farm 
near Richmond, Indiana. Attended country school; 
a nearby high school; and Earlham College. “Ex- 
plored”’ wheatfields and timber regions of Northwest, 
and cattle ranges and mining camps of Southwest 
United States. Came to Washineton, pian 
1890, and served as secretary to Sumner I. Kimball, 
U.S. Life Saving Service. Resigned in 1895 to take 
up inventing as a profession. Built the prototype 
of the motion picture projector now in every picture 
theatre the world over; developed the spiral-wound 
paraffined all-paper container; and produced the first 
photographs by radio, and mechanism for viewing 
distant scenes by radio. Has over three hundred 
patents; and maintains a private laboratory in 
Washington. He is a member of the Franklin Insti- 
tute, the American Association for the Advancement 
of Science, and founder of the Society of Motion 
Picture Engineers. Has several times been honored 
by scientific and other bodies for original research 
and attainment. 


Foreword 


The rapid development of apparatus for the trans- 
‘mission of photographs by wire and by radio may 
now be confidently expected, because the public is 
ready forit. At this very moment it is going through 
the same empirical process by which motion pictures 
arrived, and out of which finally the long film strip 
was born. 

In the motion picture development there appeared 
the spiral picture disc; the picture “thumb book’’; 
picture cards radially mounted on drums and bands; 
and the picture film continuously moved and inter- 
mittently illuminated. 

But finally the development resolved itself into a 
single, long, transparent picture film, intermittently 
moved in the exposure aperture of the projecting 
machine; and upon this has been built one of the 
large industries of the world. 

Doubtless this will be the history of the develop- 
ment of electrically transmitted photographs, and of 
radio vision, for many schemes have already been 
tried and more may yet be seen before the final, 
practical form shall have been evolved, and this new 
aid to business and to entertainment shall have taken 
its place in human affairs. 

The transmission of a photograph electrically, a 
portrait, for example, is not so much a matter of 
mechanism, once the tools are perfected and their 
operation understood; it is more a matter of blending 
of line and tone, just exactly as it is with the artist. 
The great portrait photographer uses the same tools 
the amateur uses, but an acquired technique of high 
order enables him to produce a superior portrait, 

5 


free of chalky contrasts, and soft in tone and blend- 
ing. Just so in radio photography, it is a matter of 
simple mechanism, and an acquired skill in its use. 

The author expects to see, very soon, the radio 
amateurs using flash-light lamps and electric pens 
where they now use headphones; and halftones or 
potassium cells where they now use microphones, 
for the radio problem between the two is practically 
the same—if anything rather more simple with 
light than with sound. And new means for modulat- 
ing electric current by changing light values may be 
expected when the American boy starts to play with 
this new toy. 

There has been a veritable army of engineers 
engaged in the development of radio as a service to 
the ear, while relatively few engineers have been 
developing radio as a service to the eye. 

It is believed that the distant electric modulation 
of light for many purposes will soon become a common 
phenomena and eventually of inestimable service in 
science, in engineering, in industry, and in the home. 

Nor will this service be confined to radio. Present 
metallic channels now employed for other purposes, 
1. e., high tension power lines, railroad rails, city 
lighting wires, and water pipes, can be made a new 
source of revenue, and at a ridiculously insignificant 
cost. 

Radio is none the less valuable by reason of its 
application as such a rider on the present metallic 
grids of every city, and of interurban connections. 
There are many channels where only space radio can 
be employed, but the neglect of the application of 
high frequency currents to metallic channels which 
lead into every place of business, and into every 
home, is unnecessary waste. | 

The author confidently believes the application of 


6 


these several ideas to the control of light at distant 
points is the next great advance in electricity, and to 
hasten such development the information in the 
following pages is set down to assist the research 
worker and the application engineer. The mechan- 
isms and circuits herein disclosed may be accepted 
with assurance. 

With a radio photographic technique, the result of 
ten years of concentration on this subject, it may be 
asserted with confidence that the requirement of a 
particular application rather than a particular 
machine is the governing factor in each case; for 
with full working knowledge of the art, and the 
special application requirements known, the design 
of the machine best adapted to that service is a 
simple matter. 

THE AUTHOR. 


Contents 


Page 
Amstutz Machines....... 73 
Avid. ST, Co, Picturesss7 85 
Baker’s Scheme.......... (i 
Belin Machine........... 83 
Braun Tube Receiver... .. 91 
GapillarysPen* ten 20 arene 40 
Gircwite’tadiow: ener r 117 
Code Pictirést. 232. es 89 
Colomby Radigv gaara . 93 
Control One ee ee 29 
Corona Lamp? see ee 51 
Dot Pictures +, -o ee 88 
Duplex Machine......... 105 
Electrograph of 1900..... TES 
Electrolytic Receivers..... 46 
Engraving Receiver...... 73 
Eve Radio Service....... 39 
FilamentsUanip ee 28, 50 
First Radio Channel...... 67 
First Picture Machine... .120 
Fournier and Rignoux.... 81 
Galvanometét = 32 ceLe 48 
Genesis of Radio......... 127 
Glow Campa .0 ere 29 
Halftone, filled in........ 41 
High Speed Camera...... 25 
Historical Sketch, Jenkins.118 
Hook-ups—Jenkins....... 117 
Initial Activities aa. a. 25 
Ink Pen Receivers ....... 46 
Korn, Dr., Machine...... 79 


Lens Drum Machine...... 116 
Lens Disc Machine. .114, 115 
Light Cell ee 42 


Page 
Light Sources 7) saa 112 
Light Wedge...cc5 eee 48 
Mechanisms employed.... 40 
Medals... eae 121-126 
Motion Picture Projector. .120 
Multiple Signals......... 30 
Nipkow & Suttonsa aes 71 
Oscillograph Receiver..... 47 
Patents, list Grasse 132 
Perforated Strips. yee 
Photographic Receiver.... 47 
Pneumatic Valve......... 49 
Prismatic Ring... .25, 98, 110 


Prismatic Ring Machines. 95 


Radio Circutte3a55eaaee 117 
Radio Corp. Pictures..... 87 
Radio Motor] ae 30 
Radio Visions... ee 33 
Radio Vision Machines. . . 109 
Receiving Machines...... 45 
Receiving Methods. = 26 
sending Machines........ 40 
Sources of [ight? 2a 112 
Spark Gap Source........ 50 
Strip Machines. .a 103 
Stroboscopic Lamp....... 30 
Sutton & Nipkow........ 71 
swelled Gelatin: 72a 41 
Synchronizing Forks..... 101 
Talking Machine....... relies 
Transmitting Methods.... 25 
Washington ?: 3... 133 
Zinc Etching 3). 40 


Illustrations 


Page 
Peto 1, Co-example... 84 
Amstutz Machine........ 72 
Baker Machine.......... 76 
Belin Machine:.......... 82 
eee ICUUTE. . 2... oe ees 89 
PGP IaentSe ss. kc... 52-66 
PROTO cre... es 100 
MDGteEiCLUTe. 4 tan. ok 88 
Pio eNiachinie......... 104 
Cw wietgn 6) ta 74 


Examples Photograms. .35-38 
Examples Radio Photos.17—23 
Experimenter’s Machine. . 106 
Peer iouire Projector... .120 


High Speed Camera...... 124 
Pomme aampie,.......... 78 
Pee OVIICeS.....5....5.. Lt 
Coons Wireless......... 68 


Page 
INiedaIs een es ae 121-126 
POLOOTARIS Iter, 1a. ths 3208 
Prismatic Band Ring..... 99 
Prismatic Dise King 29... . 97 
Prism Combinations. .110, 111 
Radio Color Example..... 92 
Radio Corp’n Picture..... 86 
Radiowiodkoup sss. 117 
Radio Photographs... ..17—23 
Radio Photo Camera..... 96 


Radio Photo Transmitter... 94 
Radio Picture Scheme. ...113 
Radio Vision Machines. . .108 
R. V. Mechanisms... .114-116 


pecing Dvenatiow a S42: 80 
peeing by Wire... .....4-. 70 
LOL a VV OL Ceee eer An 1, 122 


olan] JNU Rekal@nbr holt, Gangs einen 102 


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Vision by Radio 
C. FRANCIS JENKINS 


HE earliest attempts to send pictures and to see 

electrically date back some fifty years, being 
practically coincident with efforts to transmit sound 
electrically. 

At first a metallic circuit was employed to carry 
the impulses representing picture values, but when 
radio was available several workers immediately 
began the adaptation of their apparatus to radio 
circuits. 

Some remarkably fine examples of pictures trans- 
mitted by both wire and radio have been produced 
in recent months; most of them showing the lines, 
but some of them without lines at all, z. e., true 
photographic results. | 

And as the transmission of images from living 
subjects in action differs from “‘still’’ pictures only 
in that they are more rapidly formed, it naturally 
followed that the solution of this problem should 
also be undertaken. 

When radio service to the eye shall have a com- 
parable development with radio service to the ear, a 
new era will indeed have been ushered in, when 
distance will no longer prevent our seeing our friend 
as easily as we hear him. 

Our President may then look on the face of the 
King of England as he talks with him; or upon the 
countenance of the President of France when ex- 
changing assurances of mutual esteem. 

11 


The general staff of our Navy and Army may see 
at headquarters all that a lens looks upon as it is 
carried aloft in a scouting airplane over battle front 
or fleet maneuvers. 

And from our easy chairs by the fireside, we stay- 
at-homes can watch the earth below as a great ship, 
like the Shenandoah, carries our flag and a broad- 
casting lens, over the mountains and plains, the 
cities and farms, the lakes and forests, of our wonder- 
ful country. 

In due course, then, folks in California and in 
Maine, and all the way between, will be able to see 
the inaugural ceremonies of their President, in 
Washington; the Army and Navy football games at 
Franklin Field, Philadelphia; and the struggle for 
supremacy in Our national sport, baseball. 

The new machine will come to the fireside as a 
fascinating teacher and entertainer, without language, 
literacy, or age limitation; a visitor to the old home- 
stead with photoplays, the opera, and a direct vision 
of world activities, without the hindrance of muddy 
roads or snow blockades, making farm life still more 
attractive to the clever country-bred boys and girls. 

Already audible radio 1s rapidly changing our social 
order; those who may now listen to a great man or 
woman are numbered in the millions. Our President 
recently talked to practically the whole citizenship 
of the United States at the same time. 

When to this audible radio we add visible radio, 
we may both hear and see great events; inaugural 
ceremonies, a football, polo, or baseball game; a 
regatta, mardi gras, flower festival, or baby parade; 
and an entire opera in both action and music. 

Educationally, the extension worker in our great 
universities may then illustrate his lecture, for the 
distant student can see as well as hear him by radio. 

12 


It is not a visionary, or even a very difficult thing 
to do; speech and music are carried by radio, and 
sight can just as easily be so carried. 

To get music by radio, a microphone converts 
sound into electrical modulation, which, carried by 
radio to distant places, is then changed back into 
sound and we hear the music. 

To get pictures by radio, a sensitive cell converts 
light into electrical current, and at radio distances 
changes these currents back into light values, and 
one may see the distant scene; for light is the thing 
of which pictures are made, as music is made of 
sound. 

To further show the close relation, it might be 
added that im receiving sets these same electrical 
values can be put back either into sound with head- 
phones or into light with a radio camera; although 
it may be admitted that such radio signals do not 
make much sense when with headphones one listens 
to the pictures. 

Already radio vision is a laboratory demonstration, 
and while it is not yet finished and ready for general 
public introduction, it soon will be, for it should be 
borne in mind that animated pictures differ from 
still pictures only in the speed of presentation, and 
the sending of “‘still’’ pictures by radio is now an 
accomplished fact, radio photographs of no mean 
quality, examples of which appear as illustrations in 
this volume. | 

Just as is done in radio photographs the picture 
surface is traversed by a small spot of light moving 
over the picture surface in successive parallel adjacent 
lines, with the value of the lines changed by the 
incoming radio signals to conform to a given order, 
the order being controlled by the light values of the 
scene at the distant sending station. 


13 


In sending pictures electrically, there have been 
but two methods employed, perhaps the only methods 
possible; namely (a) a cylinder mechanism; and (0) 
a flat surface. 

Without exception, every scheme which had 
attained any degree of success, before the author 
adopted flat surfaces, has depended upon synchronous. 
rotation of two cylinders, one at the sending station 
with the picture thereon to be sent; and the other 
at the receiving station where the picture is to be 
put... ~ ; 

Perhaps the very obviousness of the cylinder 
scheme, and that there are no patents to prevent, 
explains why, it has been employed by so many. 
And there have been many workers in this line of 
endeavor; for example, in England, Lord Northcliff, 
sir Thompson, Mr. Evans and Mr. Baker; in France, 
MM. Armengaud, Ruhmer, Rignoux, Fournier, and 
Belin; in Germany, Paul Nipkow, Dr. Anchutz, and 
Dr. Korn. , | 

In America, Mr. Ballard, Mr. Brown, and Mr. 
Amstutz, the latter deserving particular mention, 
for, from a distant picture, a swelled gelatine print, 
he engraved a printing plate which could be put 
directly on a printing press for reproduction. 

All these many workers have adopted the cylinder 
method of sending and receiving, and all have arrived 
at approximately the final stage of development 
permitted by concurrent science. 

It may be well to explain that, in these older 
schemes, the picture to be sent is wrapped around 
the cylinder, usually a cylinder of glass where light 
sensitive cells are employed, mounted on a rotating 
shaft, which also has longitudinal displacement. 

The light values which make up the picture are 
converted into electric current of corresponding 


14 


values and put upon a wire or other channel which 
delivers them to the distant receiving station. 

At the receiving station a suitable film-like sheet 
(paper, for example) is wrapped around a cylinder 
similar to that at the sending station. As. this 
cylinder is rotated and longitudinally advanced 
under a stationary point in contact with the paper 
on the cylinder, a spiral is traced thereon. As the 
incoming electrical current represents picture values, 
and as the two cylinders are turning in exact syn- 
chronism, a picture duplicate of that at the sending 
station appears thereon. After the picture is com- 
pleted the paper sheet can then be taken off the 
cylinder and flattened out for such use as may be 
desired. 

It is quite obvious that vision by radio and radio 
movies can never be attained by a cylinder method, 
for as the picture must appear to the eye complete, 
by reason of persistence of vision, it naturally 
follows that the eye must make up the whole picture 
from a single focal plane. 

The attainment of “‘television”’ or Radio Vision, as 
it is now coming more commonly to be called, requires 
that the sending shall be from a flat plane, and 
reception on a flat plane, and a modulation which 
will give not only the high lights and shadows but the 
halftones as well. 

These ‘“‘flat planes’’ may, of course, be the focal 
planes of the lenses employed at the receiving station, 
and from the focal depth of the lens at the sending 
station where the picture may perhaps be taken from 
living actors in the studio or from an outdoor scene. 

At the receiving station the ‘“‘flat surface’? may be 
a photographic plate, a white wall, or a miniature of 
the usual “‘silver sheet’”’ of the motion picture theatre. 

It may aid in a clearer and quicker understanding 

15 


of the text if the words telephone and television be 
limited to metallic circuit service, while radio phone 
and radio vision is applied to radio carried signals, 
and this designation will be employed in the following 


pages. 


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This and succeeding pages are examples of photographs re- 
ceived by radio from a distance, by the Jenkins system, some 


of them from Washington to Philadelphia, and represent the 
best work done in 1922, 1923, and 1924. 


Pte LIVITIES: 

The author’s work began with the publication in 
the Motion Picture News, of October 4, 1913, of an 
article entitled ‘‘Motion Pictures by Wireless.’’ This 
contemplated the employment of a flat receiving 
surface, but in the light of subsequent experience 
the scheme proposed therein is believed to be im- 
practical. It did, however, provoke discussion of 
the subject and initiated the work which was there- 
after rather continuously prosecuted, except for 
interruption to aid in the great World War. 

After failure to find a practical, workable mecha- 
nism made up of devices already in use in applied 
science, diligent effort was made to discover the 
necessary, missing part. 


PRISMATIC RING: 


At length a device described as a prismatic ring 
was developed, a new contribution to optical science. 
In use it is comparable to a solid glass prism which 
changes the angle between its sides, giving to a beam 
of light passing therethrough a hinged or oscillating 
action on one side of the prism while maintaining a 
fixed axis of the beam on the other side of the prism. 

As a convenience in fabrication this prismatic 
ring is ground into the face of a glass disc of suitable 
size, of selected mirror plate, which gives the ring 
its own support on the rotating shaft upon which it 
is mounted. 


TRANSMITTING METHODS: 
Success in sending pictures by radio from flat 
photographs and receiving them on flat photo nega- 


2 


tive plates (and subsequently of radio vision), 
really began with the perfection of automatic 
machines for the making of these prismatic rings, 
for by means of these prisms and a light sensitive cell 
at the sending’ station the light values which make 
up the picture are converted into electrical values, 
and broadcast. 

So to put this picture on a radio carrier wave we 
simply slice up the picture (figuratively) into slices 
one-hundredth of an inch in width, in the best pic- 
tures, by sweeping the picture across the light 
sensitive cell by means of these rotating prismatic 
rings. With each downward sweep the picture is 
moved one-hundredth of an inch to the right until 
the whole picture has crossed the cell, the cell con- 
verting the light strengths of the different parts of 
each such slice into corresponding electrical values. 

The process very much resembles a bacon slicer 
in the market, each slice showing fat and lean. 
Similarly these imaginary slices of our picture show 
light and dark parts, and these lights and shadows 
moving across the sensitive cell produce correspond- 
ing strength of electric current, modulating the radio 
carrier wave of the broadcasting set accordingly. 

Further, of course, it is immaterial whether the 
current modulation is taken directly from a flat 
photograph, from a solid object, or from an out-door 
scene at which the transmitter is pointed. 


RECEIVING METHODS: 


To put these light values back together again at 
the distant receiving station to make up a negative 
of the picture being broadcast from the sending 
station, it is only necessary to reverse the process; 
first, with a point of light to draw lines across a 
photographic plate, which the rotating prismatic 

26 


rings do; and, second, to vary the density of the 
different parts of the successive lines corresponding 
to lights and shadows of the picture at the sending 
station, and this the varying strength of the incoming 
radio signal does by varying the intensity of the 
light. 

Dense areas in the negative are built up where the 
light is successively very bright at the same place in 
adjacent lines; halftones where the light is less 
intense; while where the light is very faint, little or 
no exposure occurs, and shadows will result. 

It is thus the lights and shadows which make the 
picture are built up, line by line, for when this 
negative is developed, and paper prints made there- 
from, the dense areas produce high-lights in the 
picture; the less dense areas the halftones; and the 
thin areas the shadows of the picture, person or 
scene broadcast at the sending station. It is simply 
that a photographic negative has been made of 
what the lens at the sending station is looking at. 

So, then, to receive pictures by radio, it is only 
necessary (1) to cover a photographic plate in 
parallel adjacent lines, and (2) to vary the density 
of the lines, to build up the shadows, the halftones, 
and the high-lights of the picture. | 

If one puts a nickel under a piece of paper and 
draws straight lines across it with a dull pencil, a 
picture of the Indian appears. And that 1s exactly 
the way photographs by radio are received, except 
that a photographic plate is used instead of a piece 
of white paper, and a pencil of light instead of the 
pencil of lead, the light pencil changing the exposure 
in various parts of the successive adjacent parallel 
lines by reason of the variation of the incoming radio 
signals. 

The scheme is just a long camera with miles instead 

PH 


of inches between lens and plate. For example, the 
lens in Washington and its photographic plate in 
Boston; with this exception, that the one lens in 
Washington can put a negative on one, ten or one 
hundred photographic plates in as many different 
cities at the same time, and at distances limited 
only by the power of the broadcasting station, radio 
instead of light carrying the image from lens to plate. 

The time for transmitting a picture depends upon 
the size of the picture and strength of light, say, 
from three to six minutes, using a filament lamp as a 
source. 

The radio photograph receiving instruments are 
rather simple and inexpensive and, like a loudspeaker, 
can be attached to any standard amplifying audio- 
radio receiving set. 


FILAMENT LAMP: 

For the light source for radio photographs a fila- 
ment lamp is employed, and in a single turn coil 
enclosed in a hydrogen atmosphere. This miniature 
filament coil is imaged on a photo negative plate, 
and the variation in the light is caused by putting 
the incoming radio signals through this lamp, per- 
haps after the filament has been brought to a red 
glow by a battery current. By adjusting the speed 
of the motor to the temperature change of this 
filament soft gradations of light and shade are 
obtained which probably can never be equaled by 
any other device, a photograph of true photographic 
value, entirely free of lines. : 

The author wishes to take this occasion to express 
his appreciation of the splendid assistance of the 
General Electric Company, under the personal 
supervision and hearty cooperation of Mr. L. C. 
Porter, who from the very first has shown his con- 

28 


fidence in the ultimate successful conclusion of this 
development. 


GLOW LAMP: 


For the high speed radio photograms, where only 
blacks and whites are needed, a corona glow lamp of 
very high frequency has been developed. This lamp 
is lighted by the plate current of the last tube of the 
amplifier; and as the lamp can be lighted and ex- 
tinguished a million times a second, it is obvious 
that the permissible speed is almost limitless, and a 
thousand words per minute is believed ultimately 
possible. 

This lamp has been developed for the author by 
Professor D. McFarlan Moore, an expert in lamps 
incorporating this phenomena, and who some years 
ago, it may be remembered, produced a lamp of this 
type more than two hundred feet long. It is prob- 
ably safe to predict that no other lamp will ever be 
able to compete in speed. 

As photography is the quickest means of_copying 
anything; and radio the swiftest in travel, it seemed 
logical that the two hitched together should con- 
stitute the most rapid means of communication 
possible. 


CONTROL FORK: 


Of course, the sending machine and the receiving 
machines must run in exact synchronism. This 
synchronous control of the sending and receiving 
motors is maintained by the vibration of a rather 
heavy fork at each station, and adjusted to beat 
together, with such slight automatic correction by 
radio as may be required to keep all receiving forks 
in step with the fork of the station which at the 
moment is sending. It is a very simple and depend- 

29 


able mechanism, by which any number of motors, of 
any size, separated by any distance, can be made to 
run in synchronism. 


RADIO MOTOR: 


Another scheme of the rotary type, perhaps even 
better adapted to the distant control of large motors, 
is a small synchronous radio motor driven by power 
carried by radio from the broadcasting station to the 
receiving stations. It is, of course, rotated partly by 
radio power from the distant station, and partly by 
local current, just as a loudspeaker is operated. 
These small motors, rotating in synchronism with 
the motor at the sending station, control the rotation 
of a larger motor in each receiving camera, and so all 
stations keep in step. 


STROBOSCOPIC LAMP: 


Of course, it would be fatal if it were necessary to 
wait until the picture was developed before it could 
be discovered that the receiving camera was getting 
out of control. So a special ‘‘neon’’ lamp is located 
to shine on a revolving marker on the motor shaft 
of the receiving instrument, and flashed by the incom- 
ing radio signals, which latter bear a definite relation 
to the rotation of the sending station motor. 


SAME WAVE: 

It should be noted that the same radio wave 
carries both the picture frequency which builds up 
the photograph and the synchronism frequency which 
controls the’ motors, and also that it lights the 
stroboscopic lamp. ai 


MULTIPLE-SIGNAL RADIO: 


A further advance step was made when an audible 
message was added to the same radio wave which 
30 


carried the picture. This is done by modulating 
the carrier wave to give audibility, while interrupting 
the same carrier wave at a frequency far above the 
audible range, say, two hundred thousand cycles, to 
make our picture. 

By means of this duplex employment of the same 
radio wave, it is possible to get, for example, both 
the gesture and the voice of an inaugural address; 
the play and the cheers of a national sport; or the 
acting and song of grand opera. 

Perhaps it might be explained that synchronism 
in visual-audible radio reception is accomplished by 
the simple expedient of keeping the radio picture 
“framed,’ exactly as this is done in the motion 
picture theatre. 

But continuing the description of the still picture 
processes a little further, before taking up Radio 
Vision and Radio Movies, it might be added that 
while photographs by radio is the more interesting 
and impressive process, there is little doubt but that 
radio photo letters will be of much greater immediate 
service in business. 

Commerce, like an army, can go forward no faster 
than its means of communication. The history of 
industrial advance in all ages shows that with every 
addition to communication facilities the volume of 
business has increased. Obviously a third electrical 
means of communication will enlarge business, and 
speed up commerce and industry. 

As an aid in national defense the chief of staff of the 
Signal Corps of the Army, in a recently published 
report to the Secretary of War, said (Washington 
Star, November 22, 1924): 


“Looking into the future of signal communication 
for a moment, it appears that the basic method of 
breaking messages up into words, words into letters, 


Jl 


letters into dots-and-dashes, and then passing these 
through the wrist of an operator, as has been the 
practice since Morse’s fundamental invention of the 
electric telegraph, seems to be nearing the end of a 
cycle. Mechanical transmitters with higher speed 
qualities are becoming stabilized and American 
invention seems to be making further and rapid 
progress in associating photography with~ radio, 
which bids fair to revolutionize fundamental methods 
of transmission. 

‘“The message of the future, whether it be written, 
printed, of mixed with diagrams and photographs, 
including the signature of the sender, will, it seems 
certain, soon be transmitted photographically by 
radio frequency at a rate tens of times faster than 
was ever possible by the dot-and-dash methods of 
hand transmission. 

‘Military messages of the future, particularly in 
active operations, may contain diagrams and 
sketches, or even entire sheets of maps, all trans- 
mitted as part of the same message and by means 
of which detection or listening-in will be reduced to 
a very low minimum.” 


The author suggests that it might be added that 
the newcomer, the radio photogram, has merits 
distinctly its own, e. g.: 

(1) It is autographically authentic; (2) it is photo- 
graphically accurate; (3) it is potentially very rapid; 
(4) it is little effected-by static; (5) it is not effected 
by storms; and (6) it is automatic and tireless. 

It can also be used to enlarge the individual news- 
paper’s influence and prestige by the establishment of 
photostat branch printing plants at strategic points, 
like summer camps, and winter resorts, and at 
ridiculously little cost. 

Such copies of the news, financial and market 
report pages of the paper could be distributed in 
these distant places before they could possibly 
appear on the streets of the home city of the paper. 

32 


Of course, produce market reports, stock market 
news, and similar matter could be so distributed very 
much quicker than could be done by any other 
system, certainly so to the farmer and gardener. 


RADIO VISION: 


Radio Photographs and Radio Vision, when both 
are done by the flat-plate method, are identical in 
principle, the difference being only in the speed of 
the apparatus, with such modification in the appara- 
tus as will permit of the required speed. 

Just as in the Radio Photograph the picture surface 
of the Radio Vision is covered with a small spot of 
light moving over the picture surface in successive 
parallel lines, with the light value of the lines changed 
by the incoming radio signals to conform to a given 
order, the order being controlled by the distant 
scene at the sending station. 

And as the whole picture surface is covered in 
one-twelfth to one-sixteenth of a second, persistence 
of vision of the human eye is sufficient to get the 
picture from the white receiving screen—a photo- 
graphic plate is not necessary. 

When the machine of Radio Vision is turned over 
slowly, the little spot of light on the screen which 
makes up the picture looks for all the world like a 
tiny, twinkling star as it travels across the white 
surface of the screen in adjacent parallel lines, chang- 
ing in light value to correspond in position and inten- 
sity to the light values of the scene before the lens 
at the broadcasting station.» 

But when the machine is speeded up until the suc- 
cession of lines recur with a frequency which deceives 
the eye into the belief that it sees all these lines all 
the time, then a picture suddenly flashes out on the 
white screen in all the glory of its pantomime mystery. 

33 


To accomplish this, the apparatus must be speeded 
up until a whole picture can be assembled on the 
screen, say, in one-sixteenth of a second, to be seen 
by the eye directly. 

It was necessary to modify the Radio Photo 
apparatus to permit this increase-ins speeding 
lens disc is substituted for the fast pair of prismatic 
plates. Each lens draws a line while the relatively 
slow rotation of the prismatic plates distributes the 
lines over the whole picture surface, just exactly as 
the plates do in the Radio Photo Camera. 

The Radio Vision receiving set and the Radio 
Movies set are identical, and one may, therefore, 
see in one’s home what is happening in a distant 
place, an inaugural parade, football, baseball, or 
polo game (and we call it Radio Vision); or one may 
see the motion picture taken from the screen of a 
distant theatre (and we call it Radio Movies). 

The Radio Vision receiving set, as now designed, 
is very simple; namely, a mahogany box, or small 
lidded cabinet, containing, beside the radio receiving 
set and a loudspeaker, only a small motor rotating a 
pair of glass discs, and a miniature, high frequency 
lamp for outlining the pantomime picture on a small 
motion picture screen in the raised lid of the cabinet, 
synchronism being maintained by the simple expe- 
dient of ‘‘framing’’ the picture on the screen exactly 
as this is done in a moving picture theatre. 

The author wishes to acknowledge his indebted- 
ness to his friend, Professor D. McFarlan Moore, 
for a word name for this new device, i.e., ““telorama”’ 
for the radio vision instrument, and ‘‘teloramaphone”’ 
for the instrument when it includes simultaneous 
reproduction of the music or sound beac 2 
the living scene. 


34 


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RADIO SERVICE TO THE EYE: 


‘Since the initiation of broadcasting, a veritable 
army of engineers have been devoting themselves to 
the development of radio as a service to the ear. 

The author for several years has been, rather 
lonesomely, devoting his efforts to the development 
of radio as a service to the eye. 

Incidentally it is suggested that there are un- 
dreamed of possibilities in radio in the unlimited 
frequencies above audibility, in which speed trans- 
mission is greatly accelerated by the tolerance of 
eyesight, not possible in an appeal to the ear. Wit- 
ness, the motion picture theatre screen upon which a 
picture is taken off and put back again forty-eight 
times per second without discovery by the eye; while 
Piemeteutest error in a note in the orchestra is 
detected at once and grates harshly on the ear. 

Just as the motion picture depends for success on 
the fact that the eye is easily deceived, so in Radio 
Vision the eye is fooled into the belief that it sees the 
radio picture as a whole, though in fact the eye sees 
at any one moment only the tiny spot of light by 
which, with almost lightning like speed, the picture 
is made up. 

Audio radio engineers have been working in the 
very limited audio-frequency band below, say, ten 
thousand cycles, whereas the workable range where 
light instead of sound 1s employed goes away up to 
millions of cycles. It is confidently predicted that 
the next great development in radio is in this area. 

When the ‘‘teloramaphone’”’ is made generally 
available, then pictures. at the fireside sent from 
distant world points will be the daily source of news; 
the daily instructional class; and the evening’s 
entertainment; and equally the long day of the sick 
and shut-ins will be more endurable, and life in the 


39 


far places less lonely, for the flight of radio is not 
hindered by rain, or storm, or snow blockades. 


MECHANISMS EMPLOYED: 


The successful study of the problem of the trans- 
mission of light effects electrically (vision, pictures, 
light signals, etc.) might well begin with the division 
of the subject into its elements and sub-elements. 

The major division is, naturally, into (a) the 
sending station apparatus; and (b) the receiving 
station apparatus. A great variety of devices have 
been invented for analysis of the picture at the 
sending station, and the translation of the light values 
(which make up the picture) into electrical modula- 
tion; and likewise a variety of methods for receiving 
these electrical signals at a distant place (or places) 
and there changing the electrical modulations back 
into light values with which the picture is built up. 


SENDING MACHINES—ZINC ETCHING: 

Before the refinement of light sensitive cells, actual 
electrical contact was oftenest employed in sending 
the impulses which represented light gradations in 
the picture. 

Usually, therefore, a zinc etching of a pen and ink 
picture was made, and curved into acylinder. This 
picture cylinder was then slipped onto a rotating 
mandril, which was also moved axially by a screw 
thread on the mandril shaft; or the cylinder rotated 
and a contact arm moved along by the screw, like 
the old wax cylinder phonograph. 

A delicately suspended arm, moved along by the 
screw as just described and carrying, instead of the 
phonograph sound box, a very small and smooth 
point which was lifted by the high parts of the zinc 
etched picture. When so lifted the arm makes 

40 


electrical contact with an adjustable point and 
current is put into the inter-station wire circuit. 

By this means the values of the picture are con- 
verted into corresponding duration values of an 
electric current, and put onto a wire connecting the 
sending machine with a distant receiving machine 
(described in detail later in the text). 

It will thus be seen that the electric impulses sent 
out over a wire attached to the contact point repre- . 
sent the value of the light and dark portions of the 
picture. 

The electric impulses are similar to letter-code 
dots-and-dashes, for the picture actually opens and 
P@seemunencircuit, like a telegraph key, the dark 
portions of the picture sending dashes and the light 
portions of the picture sending dots. With the 
point set at one end of the cylinder, and the contact 
arm advancing longitudinally by reason of the thread 
on the shaft, the point traverses a spiral around the 
cylinder until the whole picture is covered. 


SWELLED GELATINE PRINT: 


In another process a swelled gelatine picture print 
was used to raise and lower the contact-making arm, 
and a carbon contact button was employed, but 
otherwise the sending machine was much the same. 


FILLED-IN HALFTONES: 


Somewhat later halftones of photos were available, 
and these were similarly bent into cylinders. The 
interstices between the metal points of the halftones 
were filled with an insulating wax, and the whole 
smoothed off until the bright metal points (of different 
size and representing the different values of the 
picture) were exposed. 

When this picture cylinder was rotated under a 

41 


contact point, the cylinder and the point being 
parts of an electric circuit, current flowed in the 
circuit whenever the point touched the metal parts 
of the picture, but no current flowed when the 
insulation passed under the point. 

Because the point does not jump up and down, 
but has a smooth surface to ride on, greater speed 
and accuracy is possible with the filled-in etching. 


LIGHT-SENSITIVE CELLS: 

As is quite generally known there are certain 
‘“‘semi-metals’’ which have the property of changing 
their resistence to an electric current when light falls 
thereon. 

Of this group selenium is typical, although there 
are several others, thalium, strontium, barium, etc. 

More recently it was discovered that some of the 
rarer alkali metals had the property, under certain 
conditions, of actually converting light into electric 
current. In this group are potassium, sodium, 
caesium, rubidium, etc. 

These light-sensitive cells vary the electric current 
quite accurately in proportion to the intensity of 
the light falling thereon, and when available were 
quickly seized upon by the workers in “pictures-by- 
electricity.” | 

When these light sensitive cells were employed, 
a modification of the previous picture-translating 
methods and mechanisms was made, for now a 
modulation instead of an interruption of the electric 
current was possible, the modulation representing 
the values of the halftones of a picture transparency 
as well as its blacks and whites. 

The rotating cylinder now employed was of glass, 
around which the picture, on transparent film, was 
wrapped. Inside the cylinder a light was put to 

42 


= 


shine through the passing picture film as a minute 
point of light falling on the light sensitive cell 
located in a dark box. 

Just as in the other cylinder schemes the picture 
is made to traverse this point of light until the whole 
picture is converted into electric current of cor- 
responding values, which, as before, can be put on 
a wire, or can be made to modulate a radio wave. 


PERFORATED PAPER STRIPS: 


One of the oddities of picture analytical translation 
consists of running a perforated paper strip between 
a source of light and a light sensitive cell, the paper 
ribbon perforated with a series of groups of holes. 

It is intended that the number of holes in succes- 
sive groups along the ribbon shall represent succes- 
sive values of light in the different parts of the picture 
to be transmitted. 

While it is possible to perforate such a ribbon it is 
quite likely that the experienced engineer would 
adopt some of the simpler forms of picture transla- 
tion, for there are enough of them which may be 
used without hesitation, such basic patents as have 
ever existed having long since expired. 

An unusual scheme consists in writing the message 
in ink made of saltpeter, and then setting fire to the 
ink line. The ink line of the message burns itself 
out leaving the paper intact. Thereupon the paper 
is carefully laid on the metal cylinder of the sending 
machine, or on “‘silver paper’ which is put on the 
sending cylinder. The contact point drops through 
the burnt lines making contact, and the out-going 
signals, received on a like cylinder at a distant 
station, make a duplicate of the original message. 

A more satisfactory scheme is to put a thin coating 
of hard wax on a thin sheet of metal, or metal coated 

43 


papers. These sheets as wanted are laid on an 
electric hot-plate and the message, picture, or sketch, 
is written through the warm wax coating with a lead 
pencil or stylus. Then the paper with its message 
etched therein, is wrapped around the sending 
cylinder and rotated under the contact-making 
finger, which sends out the electrical impulses. 

One may also take the sketch, line drawing, or 
pen picture, to the zinc etcher (halftone engraving 
plant), and have him make a print on very thin 
metal, and develop and harden it, but not etch it. 
This will give a photographically accurate copy. 
This copy on the metal sheet can then be bent around 
the cylinder of your sending machine, and sent out 
by wire or radio, to be received at all stations tuned 
in. If etched the etching may be filled in with hard 
wax and this put on the cylinder, and run under the 
contact finger. 

It is possible to write on paper with copper sul- 
phate (blue vitral) solution, for the acidulated line 
carries the current through the paper to the metal 
cylinder beneath, and completes the circuit. The 
acid may even be strong enough to eat through the 
paper exposing the metal cylinder underneath. 

Salt water with a little glycerine to keep it from 
drying up too fast will also perform. 

Another method which has been proposed is to 
print or write on paper with sticky material, like 
Japan drier, and sprinkle thereon a fine powdered 
wax, battery sealing wax, for example. This will 
stick to the tacky lines and can be melted over a 
hot plate or in an oven. The melted wax leaves 
standing lines which will raise a contact-closing pen 
passing over it. If the lines are sprinkled with 
metallic powder a double contact pen can be used 


44 


and the mechanism is still simpler, less delicate, and 
more dependable. 

One of the newer methods of photogram transmis- 
sion is to use a rotating table, like a talking machine 
table, with a rectangular piece of paper thereon 
(tucked under at the corners), from which to send a 
communication; market bulletins, for example, broad- 
cast by a progressive newspaper to the farmers and 
truck gardener patrons in their vicinity. 

The contact point is advanced from the outer edge 
to the centre by a spiral cut on the under side of the 
table; or by a threaded edge of a detachable table- 
top and a reducing gear to move the contact arm 
across the message, or other scheme. 

(Of course, the receiving machine should be a 
duplicate of the sending machine, with suitable 
receiving surface. ) ; 

The bulletin sheet can not be advantageously used 
to the very centre, any more than a music record 
can, but this space can be employed by the broad- 
caster for printed announcements (as music disc rec- 
ords are so used), the receiving paper being furnished 
by the broadcaster. 

But of all the schemes it is very doubtful if any 
will ever equal the writing of the message or sketch 
in lead pencil on paper, and rotate it under a two- 
contact collector. The graphite of the lines makes 
contact across the twin-blade terminals, effecting 
the transmitter as would a telegraph key in the 
circuit. 


RECEIVING MACHINES: 

Coming now to the design of a suitable receiving 
machine, it will be found that an even greater variety 
of schemes have been tried. 


45 


INK PEN RECEIVERS: 

Upon a rotating and longitudinally moving cyl- 
inder, similar to that of the sending machine first 
described, a paper is put, and upon this paper, as 
the cylinder rotates, an ink pen, mounted on a pivoted 
arm, touches intermittently, being drawn down to 
ink the paper with every incoming electrical im- 
pulse, and lifted off the paper by a gentle spring. 


CAPILLARY PEN: 


In another ink and pen scheme the electric current 
is passed through a capillary ink tube to make it 
flow and black the paper; no lifting of the pen arm 
is necessary. 

As the order of these dots-and-dashes is controlled 
by the impulses put into the line by the picture at 
the sending station, a picture is built up on the 
paper on the receiving machine cylinder, a copy of 
the picture on the cylinder of the sending machine. 


ELECTROLYTIC RECEIVERS: 


In another and similar scheme a _ chemically 
treated paper is put on the cylinder, and upon this, 
as it rotates, a metallic point is gently pressed. 

When the incoming electric current from the send- 
ing station passes through the paper under the con- 
tact point an electrolysis occurs which appears as a 
discoloration of the paper. 

And as these discolored dots-and-dashes appear, 
as before, in an order controlled by the distant 
station, a picture is again built up on the paper, a 
copy of the picture at the sending station. 

One of the best solutions for the purpose is made 
up of Iodide of Potassium one-half pound; Bromide 
of Potassium .two pounds; Dextrine or Starch one 
ounce; and Distilled Water one gallon. (Use an 

46 | 


iron contact needle). There are other solutions 
made of Ferricyanide, but are not so satisfactory. 

still another scheme, the simplest of mechanisms, 
consists of a metal disc upon which electrolytic paper 
is clipped. This plate is then put on the rotating 
table of a talking machine. A rubbing electrical 
contact is made with the disc, and the other wire 
Bitacniea tO the tone arm to complete the circuit 
through the steel needle of the sound box. 

As no groove is available to carry the arm toward 
the centre of the disc, a spurred-wheel is attached 
thereto, so as to engage the paper on the disc. The 
wheel can be adjusted diagonally of the tone arm to 
give any separation required in the convolutions of 
the spiral line. 

One of the schemes employed, and with consider- 
able success for its time, consisted of an engraving 
tool, moved up and down radially of a coated cyl- 
inder, cutting a groove of varying width in the soft 
coating of the cylinder. 

When this coating was stripped off the cylinder, 
iaid out flat and hardened, it was mounted on a 
printing block, inked, and impressions taken there- 
from on a suitable printing press. 


PHOTOGRAPHIC RECEIVERS: 

But doubtless photographic paper, wrapped around 
the cylinder, has been used oftener than any other 
medium. With photo paper or film a point of ight 
is usually employed to expose the film. 


OSCILLOGRAPH RECEIVERS: 

The point sources of light used and methods of 
modulation have been almost as varied as the 
temperaments of the several workers. One of the 
first was the employment of a steady light source 
which, reflected in the tiny mirror of an oscillograph, 

47 


is caused to vibrate at a high frequency across a 
minute aperture which in turn is imaged on the 
film on the cylinder. As the amplitude of vibration 
of the mirror determines the amount of light passing 
through the aperture and falling on the film, it will 
readily be wunderstood that the strength of the 
incoming electric signals, representing light values 
of the picture at the distant station, reproduce 
duplicate values on the exposed film. When this 
film is developed a copy of the picture on the cylinder 
of the sending machine is obtained. 


LIGHT WEDGE MODULATION: 


Another scheme for modulating the light falling 
on the film on the cylinder, consists in placing a 
light wedge against the face of a lens which images the - 
vibrating mirror (or light source) on the film. 

As the light is constantly imaged on the film by 
the lens its slight displacement toward the dark end 
of the light-wedge by the vibration of the mirror 
decreases the strength of the light falling on the 
film, while displacement toward the thin edge of the 
light-wedge gives greater exposure on the film. 

It is obvious, therefore, that the vibration of the 
mirror determines the exposure at successive posi- 
tions on the film; and as these displacements follow 
the varying strength of the incoming electric current, 
and the: latter in turn is determined By wtiestcus 
values of the picture at the sending station, it natur- 
ally follows that when the film is developed a dupli- 
cate of the distant picture results. | 


SILVER WIRE GALVANOMETER: 

Another method of varying the light falling on 
the photo film on the cylinder consists in mounting 
two very minute overlapping shutters one on each 

48 


of the two wires of an electric circuit suspended in a 
strong magnetic field. On these overlapping shutters 
a light source is focused, so that greater or lesser 
displacement of the shutters, by reason of varying 
strengths of current in the adjacent runs of the wire, 
allows more or less light to pass there between. 

Another lens images these tiny shutters onto the 
film covered cylinder, so that when the shutters are 
opened by the incoming currents in the two wires, the 
light 1s concentrated on the film. 

As the exposure depends on (a) the shutter open- 
ings, and the shutter opening on (0) the incoming 
current strength, and the incoming current strength 
on (c) the light values at the sending station, develop- 
iene oretne film again gives a duplicate of the 
picture at the sending station. 


PNEUMATIC VALVE: 


An interesting scheme of picture reception is 
known as the pneumatic light valve, the vibration of 
which causes a shadow band to oscillate across a 
lens opening into the camera. 

In a circular center opening in a magnetized iron 
diaphragm is suspended an iron disc somewhat 
smaller than the opening. ‘This small disc is mag- 
netically held by its edge to the inside edge of the 
opening in the diaphragm, with its plane in the plane 
of the magnetic field of the diaphragm. 

Upon the disc is mounted a tiny mirror, and as the 
suspension of the disc is in the magnetic field held 
there by the strength of the field itself, it is extremely 
easily disturbed, so that a small beam of light 
reflected from the mirror can be vibrated with a very 
little current through great amplitude. 

As the beam of light has a transverse shadow 
band therein of a width to normally close the lens 


49 


opening into the camera, the varying amplification 
of the vibration of the mirror, and therefore, of the 
shadow, admits a proportional amount of light. 


DRARK GAL. 

One of the very simplest light sources for exposing 
the film on the receiving cylinder consists of a 
minute spark-gap located in contact with the moving 
film. 

The strength of the incoming current charges a 
small condenser until the gap breaks down and the 
passing spark exposes the film (or perhaps perforates 
it). If the current is strong the sparks pass the gap 
at a high frequency, while if the current is weak the 
frequency is less. The range may be from 500 to 
5,000 per second perhaps, depending on the current 
strength, and, of course, the film exposure corres- 
pondingly varies, and the different degrees of density 
of the picture results. 

This scheme requires about as small current as is 
likely to be practical, perhaps, especially when the 
spark is in a suitable degree of vacuum, and, of 
course, the incoming radio signals require corres- 
pondingly small amplification. 


FILAMENT LAMP: 

The direct source of light which in the author’s 
laboratory has produced the most perfect photo- 
graphic effects, 1. e., photographs absolutely without 
lines, consists of a lamp about an inch in diameter 
and two inches long, fitted with a standard screw 
base. The tube contains a .6 mil filament with a 
small single turn coil in a hydrogen atmosphere. 

The coil is offset until 1t almost touches the glass 
wall. Such location of the coiled filament permits 
the effective placing of a minute aperture in very 

50 


close relation to the filament; whereas an aperture 
on the outside of a bulb with the light source in the 
centre of the bulb acts like a pin-hole camera, and 
sharpness of image is practically impossible (unless 
a lens is used). 

The lamp described above will respond to fluctua- 
tions in current well above a thousand times per 
second, but requires voltages about four times 
normal. It was made for the author by courtesy 
of the General Electric Company, under the direc- 
iioeo. Wir, 1. C. Porter, of Harrison, N. J. 


CORONA LAMP: 


But the lamp that really elicits the author’s 
unqualified admiration is the corona glow lamp made 
for the author by Professor D. McFarlan Moore. 
It consists of a small glass bulb containing a neat- 
fitting metallic cylinder, one terminal of an attached 
circuit. Inside and concentric with the cylinder is 
a second cylindrical capsule made of a solid rod 
drilled to a predetermined depth. 

The electron stream from the outside cylinder to 
the capsule naturally takes the long path, and as the 
longest path is down into the capsule, the result is 
that the small central opening of the capsule glows 
with great intensity while the other parts of the 
lamp remain dark. This lamp, Professor Moore 
advises, has a light and dark frequency of a million 
per second. 


S1 


NEWCOMB CARLTON, PRESIDENT GEORGE W. E. ATKINS, FIRST VICE-PRESIDENT 


153W 1W 1 EXTRA OF TELEPHONED MESSAGE 
P ROCHESTER NY 114P ocT 12 1922 
C FRANCIS JENKINS 
1519 CONN AVENUE NW WASHINGTON Dc 
SOCISTY MOTION PICTURE ENGINEERS RE- 
GRETS YOUR ABSENCE FROM THE CONVENTION 
BEST WISHES FOR YOUR SUCCESS IN RADIO — 
TRANSMISSION OF PICTURES 
A R DENNINGTON SECY 
225P 


GENERAL ELECTRIC COMPANY 
) In Reply Refer to 


West Lynn, Mass. 


November 28,1922. 


Mr .C .Francis Jenkins, 
1519 Connecticut Ave., 
Washington ,)D.Cc. 


Dear Mr.Jenkins: 


I am in receipt of yours of 
November 25th, enclosing the radio pic- 
Burewetor which Io thank you. It cer- 
tainly shows a successful result. 


When I first read of your pris- 
matic ring arrangement in the "*Scien- 
tific American", I recognized that it 
Was the solution of a problem which I 
had often thought of as possible, and 
I can well understand that it may have 
applications which we do not even now 
think of. It is perfectly possible, ag 
you say, to employ the method of radio 
transmission of pictures on a very con- 
siderable scale, which would hardly be 
possible in transmitting them by the 
ordinary telegraph. 


With best regards, and grati- 
fication to know that you are progres- 
sing, I am, 


Very truly yours, 


Ebb Tharnotnn 


THE WHITE HOUSE 
WASHINGTON 


December 5,1922. 
Dear Mr.Jenkins: 

Please accept my thanks for the 
radio photograph Which you were good 
enough to send to me. The production 
of a picture in brite fashion is cer- 
tainly one of the marvels of our time 
and I am under obligation to you for 
sending me this handsomely mounted 
copy which will be preserved as a very 
much prized souvenir. 


Gratefully yours, 


Ur Cc Francis Jenkins 
1519 Connecticut Avenue, 
Washington ,D.c. 


Westinghouse Electric 


& Manufacturin¢ Company 
East Piltsburgh,Pa. 


Mr .C .Francis Jenkins, 
1519 Connecticut Ave., 
Washington ,D.c. 
March 7,1923. 
My dear Jenkins: 

I have been reading with much 
interest the newspapers giving an 
account of your succéss in sending 
photographa by Radio from Washington 
to Philadelphia. After my visit to 
your laboratory a few weeks ago when 
you told me of this proposed trans- 
mission, I have been looking forward 
to it feeling assured it would be 
fully as successful as the papers have 
related, and I want to add my congrat- 
ulations to the many you must have al- 
ready. received, and which you so well 
deserve. May your success continue. 


With kindest regards, I an, 


Yours yery sincerely, 


THE FRANKLIN INSTITUTE 
OF THE STATE OF PENNSYLVANIA 
PHILADELPHIA 


March 38,1925. 
Mr .Francis Jenkins, 
5502 Sixteenth Street ,N .W., 
Washington,D.Cc. 


My dear Mr.Jenkins: 


I want to say to you how 
delighted I was to receive your letter of 
March 6th, accompanied by.the beautiful 
examples of your success in transmitting 
photographs by radio. I enjoyed very de- 
cidedly the opportunity that you gave me 
of seeing the process of receiving these 
pictures and have found since that a num- 
ber of those whose attention I called-to 
your work, took advantage of the opportu- 
nity and were greatly pleased with the 
results. 


I can only say-that I 
appreciate to a certain extent, at least, 
the tremendous energy and persistence that 
you have put into the development of this 
new. art and’most heartily congratulate you 
on the success that you have obtained. 


I am promising myself 
that if I come to Washington at any time 
in the near future to make a visit to your 
laboratory and see you in your own private 
lair. Hoping that such an opportunity 
will not be too long delayed. I am, 


Sincerely yours, 


Live, Dye 


S. and A. Assistent. 


CHARLES FRANCIS JENKINS 
232 SOUTH 7™ STREET 
PHILADELPHIA,PENNA. 


Marcon Leth 1925. 
Charles Francis Jenkins, 
Washington,D.c. 


Dear Friend: 


The receipt of the Journal of 
the English Historical Society a few days 
ago, in which is given a list of Friends 
who have achieved distinction through in- 
ventions and in which your name is given, 
shows that we have another point of con- 
tact in addition to our exactly similar 
mames, and that is, we are both Members 
of the Society of Friends. 


If you ever get to Philadelphia, 
I hope you will stop in and see me and 
arrange to nave lunch with me, if possible. 


I have been much interested in 
the considerable amount of publicity 
given your work lately and I enclose a 
page from the Evening Bulletin, although 
I think it more than likely you have seen 
ce 


With best wishes, 


Very truly, 


Ky gee Clin 


NAVAL RESEARCH LABORATORY 
““BELLEVUE,’’ ANACOSTIA, D. C. 


21 August 1923. 
Mr .c .F Jenkins, 
1519 Connecticut Ave., 
Washinegton,D.Cc. 


My dear Jenkins: 


Thanks very much for the samples of your 
recent work. They look very good. I Was 
particularly interested in what you said 
concerning the Chinese and Japanese methods 
of transmitting telegraphy. I had heard 
something of this before but never realized 
how complicated it would make the process 
for them. 


As soon as I can get this laboratory 
well started I will'certainly find time to 
look in on’you and I hope arrangements may 
be made for continuing some cooperative 
work with you. We have designated a g3ec- 
tion of our organization’ to work on 
methods of secret communication but just 
now we are unable to put anyone on that 
work. 


I hope you will keep me in touch with 
your developments and let me know in par- 
ticular. What progress you are making to- 
Wards high speed work. One of the best 
arguments that I can make for the Navy 
taking up such work will be the matter of 
saving time in handling coded messages. 


With best regards, I an, 


Very truly yours, Ci p 


Physicist, fey a 


POPULAR RADIO 
9 EAST 40TH STREET, NEW YORK 


KENDALL BANNING, €ditor 6 Uanderhitt 99 & 4 
September 11,1923. 


C .Francis Jenkins ,Bsq., 
Boas Connecticut Avenue, 
Washington ,D.Cc. 


My dear Mr.Jenkins: 


I certainly appreciate your interest- 
ing letter of September 10th, as well 
as the three photographic enclosures. 

I am tremendously impressed, not only 
With what you have accomplished in the 
transmission of pictures by radio, but 
also with the limitless possibilities 
that you are opening up. It is entirely 
conceivable that the work you are doing 
right now may have an effect upon civ- 
ilization that will be almost revolu- 
tionary. 


You must have had a corking good time 
On your airplane trip from Omaha to 
Chicago. Yes, we have been, undoubtedly 
backward in the development of our air- 
plane commercial traffic. Some day we 
Wili make up for lost time. 


Cordially, 


INSPECTORS’ OFFICE 


ONE MADISON AVENUE 


NEwW YORK CITY 
October 66,1923. 


Dr.C.Francis Jenkins, 
Radio Pictures Corporation, 
Washington ,D.C. 


Dear Dr.Jenkins: 


Thank you for your kind 
note of October 4th enclosing some 
splendia reproductions of the message 
I wrote when I called upon you at your 
Laboratory. 


Upon my return to Ja- 
pan, I shall inform our Home authori- 
ties about the merits of your high 
speed camera and radio apparatus and 
Will also present the fine samples you 
sent me. 


By the way, kindly 
accept this expression of gratitude 
for the courtesies you extended to me 
and my associates during our recent 
visit to Washington. 


Very truly yours, 


> 


ENGINBBR-CAPTAIN, I. J. N. 


usec uf nth 
‘ his 


eae Otfice 


HARRISBURG 


October 23, 1923. 


Mr. C. Francis Jenkins, 
5502 Sixteenth Street, 
Washington, DeC. 


Dear Mr. Jenkins: 


My heartiest thanks for your letter 
of October 17th and for the copy of my first 
photograph by radio. I appreciate it more than 
I can easily say, and think it is a perfectly 
marvelous-piece of work under the circumstances. 
Also it is more than pleasant to have it from 
you, in view of our long association, and so 
beautifully mounted. 


With renewed appreciation, and heertiest 
thanks for all the trouble you took in getting it 


<4 


Sincarely your 


& 
x ves Vials 
Ps 


I339 -ISS5(7DIVERSEY PARKWAY 


CHICAGO 


December 21,1923. 


Mr .C .Francis Jenkins, 
Radio Pictures Corporation, 
Washington ,D.c. 


Dear Mr .Jenkins: — 


I was delighted to receive your letter 
of the 19th. Heartiest congratula- 
tions on making such wonderful pro- 
gress With the Radio Pictures, I am 
sure that I am going to be one of 
those fellows who can proudly say 

"I knew him when -". 


With all good wishes for.a Merry 
Christmas and a Happy New Year, I an, 


Sincerely, 


Rothacker Film Mfg.Co 


WRR:GLD 


EASTMAN KODAK COMPANY 


ROCHESTER, N.Y. 
February 18,1924. 


Mr .C .Francis Jenkins, 
Washington,D.c. 

Dear Mr .Jenkins: 

I am in receipt of 
VoimeeLetter .of nite 6th enclosing 
the copies of photographs sent by 
radio. Your feat seems marvelous to 
me and I heartily congratulate you 
upon its accomplishment. 

With kindest regards, 
I am, 


Sincerely yours, 


WILLIAM JENNINGS BRYAN 
VILLA SERENA 
MIAMI, FLORIDA 


July 29,1924. 


Mr.C.Francis Jenkins, 
1519 Connecticut Avenue, 
Washington,D.C. 

Dear Mr .Jenkins: 

I thank you for the Radio Pho- 
tograph--it is wonderful! What is 
there left to be discovered? 

Appreciating your friendly 


interest, I am, 


Very truly yours, 


DEPARTMENT OF COMMERCE 
OFFICE OF THE SECRETARY 


WASHINGTON 


February 1,1924. 
Mr .C .Francis Jenkins, 
1519 Connecticut Avenue, 
Washington ,D.Cc. 
Dear Mr.Jenkins: 

I Wish to express my 
appreciation for the photograph which 
you so kindly sent me. It represents 
avery startling development in radio 
and sometime aren I have some leisure 


I would be interested in discussing 


the method with you. 


Yours faithfully, 


CARL AKELEY 


J7TH STREET AND CENTRAL PARK WEST 


New YORK CITY 


March 16,1925. 
Dear Mr .Jenkins: 

You are perfectly wel- 
come to publish anything I may have 
written you. 

I think few people 
realize or appreciate the practical 
possivilities of the transmission of 
radio photographs and the high develop 
ment to which you have brought this 
art. I congratulate you on your suc- 
ce@ss and Wish a speedy realization of 


your dreams. 
Sincerely yours, 


Leorl be kes 


Wr .C .Francis Jenkins 
Jenkins Laboratories 
1519 Connecticut Avenue, 
Washington DC 


The First Radio Channel 


While perhaps not singly applicable to the subject 
of pictures by radio, it is certain that without the 
discovery that signals could be transmitted through 
the air without wires, we should not now have either 
audible or visual radio. 

While in 1832 Professor Joseph Henry discovered 

that electrical oscillations could be detected a con- 
siderable distance from the oscillator, it remained 
for a dentist, Dr. Mahlon Loomis, of Washington, 
D. C., to actually send the first radio messages. In 
1865 he built an oscillating circuit, and connected 
it to a wire aerial supported in the air by a kite. 
One station was set up on the top of Bear Den 
Mountain, in Virginia, not very far from Washing- 
ton; a duplicate station being set up on top of Catoc- 
tin Spur, some fifteen miles distant. 

Messages were sent alternately from one station 
to the other station, by dot-and-dash interruption of 
a buzzer spark circuit; while reception was attained 
by deflecting a galvanometer needle at the station 
which was at the moment receiving. 

In Leslie’s Weekly (1868) Frank Leslie personally 
describes these ‘“‘successful experiments in communi- 
cation without the aid of wires.’’ 

Later (1869) a bill was introduced in the U. S. 
Congress to incorporate the Loomis Aerial Tele- 
graph Company (though nobody would buy the 
stock, and it remained for others, years later, to 
reap the reward of radio broadcasting). 

In speaking on the bill, Senator Conger repeated, 
he said, the explanation that Dr. Loomis made to 
him, that— 

67 


er? 


Sa S Oy Are % a 
a 2 : Nyy att 
N hy. 


SNA 


This Illustration of Dr. Mahlon Loomis's Wireless Telegraph Set Was Made from His Original 
Drawings of His Invention Which Are on File in the Ualted States Patent Office at Washington. 


ERG Ra 


‘The system consists of causing electrical vibra- 
tions, or waves (from the kite wire aerial) to pass 
around the world, as upon the surface of some quiet 
lake into which a stone is cast one wave circlet fol- 
lows another from the point of disturbance to the 
remotest shores; so that from any other mountain top 
upon the globe another conductor which shall re- 
ceive the impressed vibrations may be connected to 
an inductor which will mark the duration of such 
vibration, and indicate by an agreed system of nota- 
tion, convertible into human language, the message 
of the operator at the point of first disturbance.’’— 
From Congressional Globe, Library of Congress. 

Perhaps it may be a coincidence, or perhaps a blood 
strain of the pioneer, that the first radio school ever 
set up by a woman should have been founded by 
his granddaughter, Miss Mary Texanna Loomis, 
Washington, D. C. 


69 


Nipkow and Sutton 


One of the most interesting examples of the at- 
tempts to see by radio was made the subject of a 
patent by Nipkow in 1884. The proposed trans- 
mitter consisted of a selenium cell and an objective 
lens, with a spirally perforated disc rotating between 
the cell and lens ‘‘to dissect the scene.”’ 

The receiving device employed the polarizing light 
valve used by Major George O. Squire, and Profes- 
sor A. C. Crehore, to measure the flight of gun shells 
at Fort Monroe, Virginia, in 1895. 

The Nipkow scheme was preceded by Shelford 
Bidwell’s device for “‘the telegraphic transmission 
of pictures of natural objects,’’ described in Tele- 
graphic Journal, 1881, Vol. 9, page 83; and later 
almost exactly duplicated by M. Henri Sutton, and 
rather fully described in Lumzere Electrique, Vol. 38, 
page 538, 1890. 


71 


The Amstutz System 


Of all the mechanisms which have been designed 
for the transmission of pictures electrically, that of 
Meorinistutz, of Valparaiso, Indiana, U. S. A., in 
the author’s opinion, stands out as the most con- 
Spicuous, not only for fine work, but for the cleverness 
of its accomplishment, the first successful picture 
being sent in May, 1891, over a 25-mile wire in 
eight minutes. 

“Mr. Amstutz was not the first to send pictures 
over wire, but he was the first to send pictures with 
halftones, the others were simply line drawings. In 
this first method Mr. Amstutz used a relief photo- 
graph. The amount of relief was in direct propor- 
tion to the amount of light which had acted on the 
sensitive gelatine, resulting in an irregular surface, 
representing in elevation all the variations of light 
and shade in a regular picture. 

“The picture received is actually a phonographic 
spiral around the receiving drum carrying the 
celluloid sheet. When finished it is removed from 
the cylinder and flattened out and a stereotype or 
electrotype made from it for relief printing; or the 
engraved celluloid sheet can be inked and printed 
immediately on the intaglio press.”” (From exhibit in 
U. S. National Museum.) 


73 


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The Electrograph 


From the accompanying illustration and title it 
will readily be seen that rather good _pictures...were 
reproduced with pen-and-ink method in 1890, 

The original of this picture was given the author by 
Mr. T. A. Witherspoon, who at the time of the 
experiment (1900) was a principal examiner in the 

U. 8S. Patent Office, and detailed in charge of the 
Patent Office Exhibit at the Buffalo Exposition, 
where, also, these machines were on exhibition. 

It may be a coincidence of passing interest that 
from Cleveland twenty-four years later the American 
Telephone and Telegraph Company sent their first 


_Wire-pietures. 


75 


1910.--Baker. 


1. PHOTOGRAPH WIRED 


The Baker Machine 


The machine of the opposite illustration, “the 
telestrograph,’”’ is the invention of T. Thorn Baker, 
Esq., of England, and “‘was used by the London 
Datly Mirror in July, 1909, and was worked by wire 
rather regularly between London and Paris, and 
London and Manchester.’’ ‘The picture to be sent 
was “a halftone photograph printed in fish glue on 
lead foil, and wrapped on a sending cylinder, rotating 
once every two seconds with a metal point riding on 
tes! | 

The receiving cylinder carried ‘an absorbent 
paper impregnated with a colorless solution which 
turns black or brown when decomposed by the in- 
coming electric current.” 

What electrolytic solution was employed is not 
stated in the report, but was probably sodium iodide 
or potassium bromide judging from the description 
of its color and behavior. 

To synchronize, the receiving drum turns faster 
than the sending drum, and is caught each revolution 
until the other catches up. (Smithsonian Report, 
1910.) 


77 


2. FASHION PLATE TRANSMITTED BY PROFES 
TELAUTOGRAPH, 


The Dr. Korn Machine 


The accompanying illustration shows the work of 
a machine developed by Dr. Korn, of Germany, and 
first used by the Daily Mirror between London and 
Paris in 1907. “On a revolving glass cylinder’ a 
transparent picture was put. He used a Nernst 
lamp and “selenium cells on opposite sides of a 
Wheatstone bridge’”’ to overcome the inherent lag of 
the selenium cell. 

Signals were sent over a wire and received on 
photographic film on a cylinder, using “two fine 
silver strings free to move laterally in a strong 
magnetic field.”’ A light was focused on the obstruct- 
ing “‘silver strings,’ which the incoming electric 
signals, passing through the “‘strings,’”’ separated to 
a greater or lesser degree “‘to widen or thin the 
photographed line.”’ 

‘“When the film is developed it is laid out flat, and 
the spiral line becomes resolved into so many parallel 
lines.’’ The sending and the receiving machines 
were synchronized by “well calibrated clocks which 
released the cylinders at end of every five seconds.”’ 
(Mr. Baker in Smithsonian Report, 1910.) 


79 


Rignoux and Fournier Scheme 


One of the early suggestions had for its funda- 
mental principle a surface studded with thousands of 
‘selenium cells’ each. a part of an individual circuit, 
and upon which a picture was projected. The idea 
was that the different cells would transmit a different 
value of current with each different intensity of 
light which made up the picture. 

At the distant station a given surface had a cor- 
responding number of tiny lamps, each attached to 
its respective cell at the sending station, and being 
lighted thereby the ensemble would reproduce the 
distant picture. 

The scheme is possible but hardly practical, for if 
only fifty lines per inch each way were sufficient on 
a picture but one foot square, there would have to 
be three hundred and sixty thousand cells at the 
sending end, and a like number of lamps at the re- 
ceiving end, each but one-fiftieth of an inch in diam- 
eter. Such a problem would seem to present difficul- 
ties, though the author himself in the bravery of 
ignorance suggested this very scheme in the Electrical 
Engineer, of July 25, 1894. (Illustration by courtesy 
of Science and Invention.) 


81 


The Belin Machine 


The ‘‘Belinograph” is the invention of Edouard 
Belin, of Paris. With these machines ‘‘the first step 
in transmitting a picture is to convert the latter into 
a bas-relief. Or a drawing can be made in a special 
ink, which, when dry, leaves the lines in relief. The 
picture when ready for transmission has an uneven 
surface, the irregularities of which correspond with 
the pictorial details. The transmitter resembles the 
cylinder of a phonograph. The picture is wrapped 
around this metal cylinder, and a style presses down 
on the picture-cylinder as it is rotated by clockwork. 
As the style moves up and down over the irregularities 
of the picture, a microphone varies the strength of an 
electric transmitting current. 

“At the receiving end another cylinder in a light- 
tight box carries a sensitized paper upon which a 
point of light is reflected from the mirror of a gal- 
vanometer actuated by the incoming current from 
the distant station.”’ ; 

Two very accurately regulated chronometers are 
employed to keep the machines in synchronism, one 
chronometer for the sending machine and one for 
the distant receiving machine. (From Review of 
Reviews, 1922.) 


83 


reece ssc 


American Telephone & Telegraph 
Company Machine 


The picture opposite is one of those sent by the 
A. T. & T. Company on May 20, 1924, by wire from 
Cleveland to New York. Some of the pictures sent 
were from photographs taken earlier, and some were 
taken only a few minutes before being transmitted. 

In the sending machine, “‘the film picture is inserted 
in the machine simply by rolling it up in a cylindrical 
form and slipped into the drum. During operation 
a very small and intense beam of light shines through 
the film upon a photo-electric cell within.”’ 

In the receiving machine, “‘the sensitive film is 
put on a rotating cylinder and turns like the cylinder 
record on a phonograph. On this film falls a point 
of intense white light varied constantly.” 

For synchronizing “‘two separate currents were 
sent over the wires, one is called the picture channel, 
the other the synchronizing channel.”’ 

“Forty-four minutes elapsed from the time the 
picture was taken in Cleveland until it was repro- 
duced in New York.” (New York Times, May 
20, 1924.) 

It seems unlikely that returns from the daily wire 
transmission of pictures can equal the day-by-day 
revenue from the wires used for the transmission of 
speech when balanced up for the principal circuit, 
phantom circuits, and carrier circuits. 


85 


hea 4, 
A ey Aeiey, 
Dry ao ; 


Radio Corporation Machine 


The accompanying “‘photoradiogram”’ is a develop- 
ment by the Radio Corporation of America, and was 
transmitted from London to New York on November 
30, 1924. 

“The transparent picture film is placed on a glass 
cylinder. An incandescent lamp inside the cylinder 
is focused in a minute beam onto the film as the 
cylinder rotates, and this transfers the light values 
of the picture into electrical impulses, in a General 
Electric Company photo-electric cell. 

“The receiving cylinder has white paper placed 
thereon, and the incoming dots-and-dashes, amplified 
in passing through a bank of vacuum tubes, are 
recorded in ink on this paper with a special vibrating 
fountain pen, drawn down by magnet coils to record 
the picture much in the style of an artistic stippled 
engraving.” ‘The cylinders of both the sending and 
the receiving machines are “rotated back and forth, 
the electric camera itself advancing down the length 
of the picture one notch at a time.” 

‘“The necessary synchronism of the two machines 
is maintained by the use of special driving motors, 
and a special controlling mechanism based on the 
constant pitch of a tuning fork.’ (See Radio News, 
February, 1925.) : 


87 


1 
-e 


weetee +. 
nan + ee re reece ences 


By courtesy of ‘‘The World,’’ New York. 
A RADIO CODED PHOTOGRAPH. 


How the picture looked after being sent from Rome | 
by radio and decoded on Professor Korn’s machine. 


The above is an example of one of the rather odd 
methods of “‘sending pictures by radio.”’ The pic- 
ture to be sent is divided into many small squares 
with varying values of dark in the squares. Seven- 
teen different grades of light in these squares are 
translated into seventeen letters printed on a tape. 

This coded picture is transmitted to a distant 
place and there decoded into dots of sizes correspond- 
ing to the seventeen values, and each dot placed in 
its corresponding square on a white paper. The 
collection of large dots builds up the dark areas; a 
similar collection of smaller dots makes up the half- 
tones; and still other collections of very minute 
dots make up the light areas. (From the New York 


World.) 
88 


LVGIS _ MBGwO MITIO MTITO 
QIjBQ QuyoQ S$DIXQ SOIsO 


TEIBQ TGGQO TMFQQ TSEUA 
TDERA SMEBUO QKEMQ OTEQQ 
MVEQQ MIEKA MEEIQ MDETQ 
MBF WQ LVGIOQ LMGKO LIGMQ 
KVFWQ KIFTOQ LDF BO LAEWQ 
LIBGO LQDQQ LUBWOQ MQAVOQ 
SAAMQ SKAMQ TDAVQ TLBIQ 
TUABTQ TXBVO TVDAA — TXppA 
VADMQ UAEIQ TWELA UBETOQ 
IXFFO TUFQQ TVFVQ TUGAQ 
TWGMQ UAGXO TSIGO TGIFO 
MQFEE QFFEQ QMFIO QSFMG 
‘QSFAQ QBEWA QAEVA MMEVQ 
QAFDM QIFDM ’ MTFFE GBREO 
OMFLG QGFLQ MREIO MTFFD 
QAR IQ QEFKQ QGFIO OIPGK 
QBFIQ QFFIO- QFFIQ QEFFM 
QHEGY QYFIS . QEEKA QFFLE 


Fig. 3. This is Part of the Program or 

Code Telegraphic Message—the Form in 

Which the Picture is Flashed Over the 

os Tes. 5 z 

Fig. 4. This is the Complete Outline Ob- ‘S : Ce 

tained from the Code, with Proper Shade : Wied oo Lf ye 
Letters Within Enclosures (Right). | Tinto Wive Decrees cf Shade 


A telegraphic code scheme in which points in a 
picture are determined by the crossing of straight 
lines, ordinates and abscissas, and in which the 
shades of light, of gray, and of black which make up 
the picture are also indicated by letters. 

This coded information is telegraphed to the distant 
stations where the receiving artist determines the 
location of these points and shades by (1) a similar 
pair of crossed straight lines, and (2) letters indicating 
the light values to be washed in on paper. 

The process depends for its success largely on the 
skill and cleverness of the receiving artist, and is 

hardly more than a “‘filler-in’’ pending the adaption 
of the directly photographic process. (Courtesy 
Science and Invention.) 


89 


The Braun Tube Receiver 


One of the theoretically attractive forms of 
receivers is the Braun oscillograph tube, for it is so 
very easy to wobble the cathode ray spot about over 
the fluorescent screen, to form figures. It has an 
imponderable pencil of light which can be moved 
So oteimeepiciire screen: with very little electrical 
energy. Its use has been proposed by many. 

But the feature of the system which is most often 
overlooked in this scheme is the necessity for an 
analytical picture machine at the sending station, 
and no such device in satisfactory workable form has 
yet been suggested. 

The Braun tube system awaits, therefore, the 
attention of the practical-application engineer before 
it can compete with other forms of receivers. 


91 


Pictures by Radio in Natural Colors 


It is well known that pictures in color are in com- 
mon use in magazine printing, in window transparen- 
cies, decorations, etc. The process consisting in mak- 
ing three negatives, one through a red screen, a second 
through a green screen, and a third through a blue 
screen. When transparencies from these three nega- 
tives, each stained in its complementary color, red, 
green and blue, are superimposed and viewed by 
transmitted light, the resultant picture is seen in its 
natural colors. 

With this process generally well known, it is 
obvious that three such negatives transmitted by 
radio or wire could be colored and combined to make 
a “picture sent by radio in natural colors.’’ Of 
course, the picture is not sent in color at all, and the 
author hesitates to claim for such a feat more than 
that the resultant picture proves the excellence of the 
synchronism of the machines employed in the trans- 
mission of the three successive pictures which after 
their reception are to be colored and combined 
into one. 


93 


Prismatic Disc Machines 


These machines are principally used in radio 
transmission of photographs; employ four overlapping 
prismatic discs or “‘rings’’ in both the sending and 
the receiving machines. Either a transparent or an 
opaque picture is used in the sending instrument; 
and in the receiving camera a filament lamp, modu- 
lated by the incoming radio signals, recorded on a 
photographic negative plate. 

In the sending machine (first illustration) the 
picture is projected with a magic lantern (1) through 
four overlapping prismatic rings, (2) two of which in 
rotation sweep the picture vertically across the light 
sensitive cell, at the same time the image is moved 
laterally by the other pair of prisms. ‘The different 
light values of the picture are changed into electric 
values in light cell 4, and broadcast. <A rotating 
perforated disc, (3) interposed between the lens and 
light-cell, produces a pulsating direct current which 
can immediately be amplified through the usual radio 
transformers, on its way to the broadcasting set. 

In the radio camera (second illustration) a photo- 
graphic negative (1) is used and a pencil of light 
from lamp 2. The rotating plates (3) draw the 
lines and the radio signals vary the light intensities 
of the lamp to give gradations of exposure on the 
negative plate. (See next page.) 


95 


The Jenkins Prismatic Ring 


The prismatic ring or plate is a new contribution 
to optical science, and was designed for use in a 
machine for the transmission of radio pictures from 
a flat surface, and for recording them on a flat surface, 
the only way in which radio vision and radio movies 
will ever be produced; and a method which permits 
of the reception of portraits having true photographic 
value, without lines, and having tone and shading 
unequaled by any other known process to date. 

The prismatic ring section is ground into the face 
of a glass disc, and from one end to a point half 
around it has its base outward, and from this midway 
point around to the other end having its base inward. 
The warp from one end to the other is gradual. 

A beam of light passing through this ring, in rota- 
tion, is caused to oscillate, having its hinged action 
fulcrumed in the plane of rotation of the prism ring. 
The oscillation is always in the plane of the diameter 
of the disc from the point where the light passes 
through the prismatic ring section. 

The plates (made with the initial grinding machine) 
may have one, two, or four prismatic sections to the 
ring, and may be made right or left hand, and in 10 
inch and in 7 inch sizes, and also in disc ring (first 
illustration) or band ring form (second illustration). 


98 


Jenkins Synchronizing Forks 


The accompanying photographs show a vibrating- 
fork-control employed to keep distantly separated 
motors in synchronism. ‘This is the motor control 
employed in the system developed by the author for 
the sending and receiving of photographs and 
photograms, by radio and by wire. 

The control unit is surprisingly simple and depend- 
able, and is believed might be found useful for many 
other purposes where it is desired to keep motors in 
step with each other which are separated by long 
distances, the control signals being sent by wire or 
by radio, and from fixed or moveable stations, on 
land, on water, or in the air. 

The fork illustrated is about fifteen inches long, 
mounted on a cast brass frame with a bakelite cover 
plate upon which the fork, motor coil, and binding 
MoOsteeatre mounted. A single cell of dry battery 
keeps the fork in vibration. 

The device is designed on a new principle, and 
has a very sharp control of the motor revolutions. 
Simple means are provided for easily verifying the 
continuity of the motor control. 

These fork motor units will control any number 
of motors of any size, at any distance, and on move- 
able or stationary platforms. 


101 


The Jenkins Picture‘Strip Machine 


In the transmission of news, market reports, etc., 
as a continuous process a long strip of paper of type- 
written copy is put into this machine, and the blacks 
and whites of the letters and figures falling on the 
light sensitive cell open and close a C. W. broadcast 
or wire circuit; which at distant points is translated 
back into light and recorded on a long strip of photo- 
graphic paper. 

This can be a continuous process if the sending 
strip is added too from time to time, and the receiving 
photographic strip of paper, as it is exposed, passes 
continuously through a developing, fixing, washing — 
and drying bath. This process might be required by 
the conditions of service. A white strip and an 
electric pen may be used instead of photo paper. 

In the sending machine the rotating prisms sweep 
the image of the typewriter line across the light 
sensitive cell; and the strip is moved longitudinally 
by winding on a drum. 7 

In the receiving machine the strip is drawn along 
while it is curved around a rotating cylinder inside 
which the modulating light is located, turned off 
and on by radio. A corona glow lamp is preferably 
employed with the photographic paper. 


103 


Jenkins Duplex Machine 


The Jenkins duplex cylinder type of machine was 
designed for simultaneously sending and receiving 
photograms, letters, maps, drawings, etc. The motor 
runs all day long, like an electric fan, in control of 
the vibrating fork. The right hand (glass) cylinder 
sends; and the left hand cylinder receives. The 
messages are put on and taken off without stopping 
the machine, and without one function interfering 
with the other. 

The machine may be used on radio or on wire, and 
is an easily operated machine, the perfect functioning 
of which can be determined by a glance at the 
perforated rotating disc illuminated by the syn- 
chronizing signal lamp. 

It is believed to be the first duplex two-way service 
machine ever built, and is complete as shown, except 
for the batteries and the radio receiving set, which 
latter may be any standard set which will operate a 
loudspeaker. 

The illustration shows a machine in which a pic- 
ture transparency and a sensitive cell is used at the 
sending cylinder; and a high speed lamp and photo- 
graphic paper at the receiving cylinder. | 


105 


eee 


“Talking Machine” Photograms 


The spring driven machine illustrated is probably 
the simplest device possible for the experimental 
study of transmission of pictures and picture mes- 
sages by radio or by wire. A conducting ink or 
pencil line on paper and put on one cylinder (or an 
insulating coating cut through with a stylus) over 
which the sending point rides for sending; and an 
electrolytic bromide (or photo) paper on the other 
cylinder under the receiving pen for receiving; the 
contact points being attached to the sending and the 
receiving sets respectively. 

The upper illustration shows a machine electrically 
driven and equipped to transmit and receive hand- 
writings, maps, sketches, pictures, etc., of an area 
of about 5.x 7 inches. The sending is from pencil 
lines on paper, the reception on electrolytic paper. 

The machine is also made with a glass cylinder to 
send from a picture transparency, and to receive on 
photographic paper. It must, therefore, be used in 
a dark or subdued lighted room to receive. 

Each machine is capable of the very highest quality 
of work of its particular kind, and is simple and easy 
to operate. 


107 


Radio Vision 


The machines here shown are the laboratory models 
used in the development of Radio Vision and Radio 
Movies for the reception in the home of broadcast 
studio performances, i. e., dancing girls, public 
speakers, pantomime, marionettes, motion pictures; 
and, by remote control, outdoor events, sports, etc. 

The lower illustration shows a 10” disc rotating 
in front of a prismatic ring, synchronized by a 
variable speed of the motor. The light is in the 
round box at the top of the standard behind the lens 
carrier, and shines through lenses and prism (onto 
a picture screen) as they pass, the light fluctuating 
in value with the incoming radio signals to make up 
a complete picture every one-sixteenth of a second. 

The upper illustrated mechanism differs from the 
lower one in that it has a second overlapping prism 
for optical correction. 

The casing enclosing the mechanism is not very 
large, and contains, besides the radio vision mechan- 
ism, the radio receiving set, and a loudspeaker, so 
that an entire opera in both action and music may 
be received. 


109 


The prismatic ring can be rotated to follow any moving 
object; e.g., a motion picture film; or if fitted with a high- 
reading automobile speedometer the speed of an airplane or 
dirigible can be read directly off a dial by the navigating officer. 


“NEW LbGHa? : 
SOURCES FoR RADIO” 


Se eas WERT I) hs 


Vibrating 
gold leaf 
electroscope 
for blinking 
a2 consfant 

light 


JOUrCe 


Spark plug YH 
light 
vouUTCE 


The rotation of the disc A carrying lenses b, c, d, etc., sweeps 
the image of the light source C across the screen F in a hori- 
zontal direction, while line displacement in a vertical direction 
is effected by reason of the changing angle of successive prism 
elements. 


The rotation of the disc A carrying lenses arranged in a 
spiral causes the light L to sweep across the screen M. A 
revolution every sixteenth second gives a motion picture screen 
effect. 


Rapio MoTrion PICTURE MECHANISM 


The rotation of the drum A carrying the lenses b, b’, b’’, etc., 
causes the image of the light source S to sweep across the 
screen Y in two directions. A complete rotation every six- 
teenth of a second is motion picture speed. 


\|1| 


|- 


OSU Ome ay 


lIbe 
[eee ye iy 


Wa 
MH = 


Radio Vision hook-up circuits. A is the light cell. The 
upper circuit puts a “‘chopper’’ frequency onto the radio carrier 
wave by the inductive coupling. 

The lower diagram shows an intermediate frequency oscil- 


lator to be controlled by a light-cell (not shown), the interme- 
diate being put on the carrier wave. 


Historical Sketch of Jenkins Radio 
: Photography 


1894. Jenkins publishes article on transmission of | 
pictures electrically with illustration of proposed 
apparatus.—Elecirical Engineer, July 25, 1894. 

1913. Proposes another mechanism, for ‘‘Motion 
Pictures by Wireless.’’—Motion Picture News, Sep- 
tember 27, 1913. 

1920. Reads paper on the Prismatic Ring, a new 
contribution to optical science (an essential element 
in transmission of radio pictures)—Tvransactions 
Society Motion Picture Engineers, Toronto Meeting, 
May, 1920. 

1922. Sends first radio photograph; sent from a 
photograph, and received photographically; and 
predicts motion pictures by radio’in the home.— 
Washington Evening Star, May 19, 1922. 

1922. Sends photographs by telephone wire of 
American Telephone & Telegraph Company, through 
his desk telephone, from 1519 Connecticut Avenue 
(Washington) to Navy Radio Station, NOF, at 
Anacostia, D. C., and there broadcast. The signals 
were picked up and recorded on a photographic 
plate at 5502 Sixteenth Street N.W., Washington, 
D. C., in presence of Commander AY) Movin ia iom 
of the U. S.. Navy, and J. C. Edgerton; or tites ass 
Office; October 3, 1922. 

1922. Makes official demonstration of his radio 
transmission of photographs for Navy officials De- 
cember 12, 1922, in presence of Admirals 8. S. Robi- 
son and H. J. Ziegemeier, Captain [7 TS Pomipiane 
Commander 8. C. Hooper, Lt. Commanders E. H.: 
Loftin and H. P. LeClair; the report of which was 
later released for publication.—Washington Evening 
Star, January 14, 1923. | 

118 


1923. Sends radio photographs of President War- 
ren G. Harding, Secretary Herbert Hoover, Governor 
Gifford Pinchot, and others, from U. S. Navy Radio 
station, NOF, Washington, to Evening Bulletin 
Building, Philadelphia, by courtesy of Robt. McLean, 
Jr., March 2, 1923.—Reproduced in the Bulletin, and 
in the Washington Star, March 3, 1923. 

1923. Makes his first laboratory demonstration 
of Radio Vision (the instantaneous reproduction on a 
small picture screen of a distant performer or a dis- 
tant scene), and of Radio Movies (the transmission 
of pictures from a theatre screen to a small screen 
in the home), June 14, 1923. See Vusitor’s Register. 

1924. Makes his first hundred-line photograph, 
June 15, 1924, portraits of true photographic values 
in which no lines appear. Photographs of President 
Calvin Coolidge, Dr. J. 5. Montgomery, Chaplain of 
the House, William Jennings Bryan, etc. See letters 
of congratulations from subjects of these photo- 
graphic tests. | 

1924. Sends message, in Japanese characters, 
from Charge d’Affairs, I. Yoshida, of the Japanese 
Embassy, Washington, 1.e., sending from the old 
Navy Station, NOF, to Amrad Station, WGI, Med- 
ford Hillside, Massachusetts; reported and repro- 
duced in Boston Traveler, December 4, 1924. 

1924. Apparatus bought and used experimentally 
by U. S. Post Office Department, on night-flying 
section, Air Mail route, New York-San Francisco, 
first message night of December 3, 1924. See James 
W. Robinson’s telegram, December 15, 1924. 

1925. Transmits Motion Pictures by Radio from 
standard motion picture film to be looked at directly 
on a small motion picture screen in the distant radio 
receiving set; Tuesday, March 31, 1925. 5S.L.A., 
eee ee NO). |. WoR., P.D. 

119 


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asn [esieArun ut 10joefoid omyord uorjoul oy} Jo edAyojo1d 9Y4 st sUTyORUT SITY], 


The accompanying cuts show the Elliott Cresson Gold Medal, 
awarded by the Franklin Institute, of Philadelphia, for a 
machine exhibited before the Institute in 1895 by Mr. C. Francis 
Jenkins. 

Later, in making a second award, that of the John Scott 
Medal, “in recognition of the value of this invention,” the 
Institute Committee said: ‘Eighteen years ago the applicant 
exhibited a commercial motion picture projecting machine 
which he termed the ‘Plantoscope.’ This was recognized by 
the Institute and subsequently proved to be the first successful 
form of projecting machine for the production of life-size motion 
pictures from a narrow strip of film containing successive phases 
of motion.”’ 


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The Jenkins High Speed Camera 


This camera was designed for the study of high 
speed motions; 1.e., the flight of birds, recoil of guns, 
the impact of shell on plate, muscular activity of 
athletes, airplane behavior, mechanical motions, etc. 

The normal rate of exposures is 1,000 to 3,000 
pictures per second (4,000 pictures per second have 
been made). 

It uses standard motion picture super-speed nega- 
“tive film. Prints from these negatives are made in 
any standard motion picture printer, and developed 
in the usual way. 

The prints may then be projected in any standard 
motion picture projecting machine, giving an appar- 
ent reduction of 100 to 200 times in the speed of move- 
ment of the object photographed, and - therefore 
easily studied. 

The camera is fitted with 48 Zeiss Tessar lenses, 
F-3.5 and 2” focus, and is driven by an automobile 
starting motor. 

It weighs approximately 100 pounds, and therefore 
easily moved from place to place. (Weight of two 
6-volt automobile batteries additional. ) 

Sunshine is adequate for illumination. If artificial 
illumination is employed, it should be equal to 
sunshine. 

(NoTE: The explanation of the unusual speed pos- 
sible with this camera lies in its lens system, for each 
lens may work as much as 150 per cent of the time; 
that is, the exposures overlap.) 


125 


The Genesis of Radio 


A Broadcast from WRC, November 20, 1924 
C. FrAnNcis JENKINS 


HE history of radio is unique—at first only a 

scientific curiosity, and for years thereafter a 
boy’s plaything; when, all at once, without warning, 
the public takes it up with a suddenness no one 
foresaw, and for which no one was prepared. 

An invention which behaves so peculiarly excites 
one’s curiosity to a study of its strange attraction; 
and of the beginnings of the scientific principles 
involved, now so knowingly discussed by mere 
youngsters. 

Why, boys in the whole range of their ’teens dis- 
course with fluency and understanding such myster- 
ies as inductance, impedence and capacities; reac- 
tance, reluctance and rotors; harmonics, aerials, and 
mush; choppers, chokes and cheese; heterodyne, 
neutrodyne, and iodine; and we oldsters don’t know 
whether they are talking of medicine, music or food. 

The only thing that saves us from everlasting em- 
barrassment is that we have the gumption to keep 
our mouths shut. 

So, determined to be ready for these ‘“‘kids’”’ the 
next time they come into my august presence, I 
start in to “bone up’’ on some of these funny words, 
and for a start I turn to a musty volume printed by 
Congress in 1879. 

It appears that on January 16 of that year the 
business of Congress was stopped, and, in solemn 
procession, led by the Sergeant-at-Arms, the Chap- 
lain, and the Vice-President, the Senate proceeded 
to the House chamber, where the Speaker handed 

127 


his official gavel to the Vice-President, who said: 
“The Senators and Members of the Congress of The 
United States are here assembled to take part in 
services to be observed in memory of the late Joseph 
Iskerenin © 

And, as I read the addresses made on that memor- 
able occasion, and look up the references cited, I get 
the solution to my problem. 

I find it was Joseph Henry who first discovered 
that breaking the circuit in a coiled wire ‘“‘gives a 
more intense spark than the same wire uncoiled.”’ 
And so inductance was born, and later in his honor 
we name its unit of measure a “‘henry.”’ 

Then he put iron inside the coil and got the first 
magnetic field; next he found that when he arranged 
a second similar coil near the first, the spark appeared 
in a gap of the second circuit, and so we have the 
first transformer. 

He put parallel metal plates across the circuit, and 
he had a condenser; and finally he separated the 
circuits by many hundred feet, and the first radio 
signals were broadcast and picked up. 

So we learn that to this modest but remarkable 
man we owe the simple coupling coil that the boys of 
the past twenty-five years have been using to tele- 
graph to each other wirelessly. 

And it is these American youngsters who have 
developed radio; who first set up two-way communi- 
cation half-way around the world; who, through 
their Radio Relay League, kept Captain McMillan 
in touch with home during his long winter night in 
the Arctic ice; who kept the Shenandoah in constant 
contact with headquarters in Washington during her’ 
recent transcontinental trip, official acknowledgment 
of which was publicly made by the Secretary of the 
Navy. 

128 


Radio eventually will touch our lives at more 
points directly and indirectly than any other dis- 
covery in the history of mankind, unless, perhaps, I 
should make an exception in favor of fire. 

And the delightful thing about it all is that the 
inaccessible places are benefited the most by radio, 
those in the out-of-the way places are less lone- 
some, and the long day of the sick and shut-in is 
more endurable. 

The farmer has his market reports on the minute, 
his weather forecasts in time for action, and he sets 
his clock by radio and gets his entertainment from 
the air. 

Dispatched and guided by radio, the flying mail 
goes day and night with such clocklike regularity 
that its remarkable performance is no longer “‘news,”’ 
although industry has not yet waked up to the ad- 
vantage and economy which can be effected by a 
larger use of the airmail. 

Ships are guided into harbor through fog by wire- 
less direction, and the captain was guided thereto by 
radio compass and radio beacon, and at sea summons 
aid in case of mishap or danger. 

famcommerce one may send. letters, telegrams, 
bank drafts, or engineer’s drawings, as radio photo- 
graphs of the originals, with photographic aero) 
and autographic authenticity. 

Men on the ground talk with men in a flying ma- 
chine out of sight in the sky, an almost inconceivable 
fact. 

This reason alone would warrant one in predicting 
that the defense of our country is definitely going to 
pass from the limited activities of the Army and 
Navy to an Air Department, for the plane has no 
boundary or limit of range in offense or defense. 

And in addition there is the wireless direction of 

129 


bomb-dropping airplanes, torpedo submarines, and 
floating mines, inanimate agencies obeying the 
distant, unseen hand. 

And ultimately power will be transmitted to 
populous areas, over wireless channels, from the 
enormous unworked coal fields away up in the Arctic 
Circle: 

The applications of radio are coming so fast in 
industry that it is hard to keep informed, but doubt- 
less its most extended use will be in the home. 

The use of microphone modulated radio to carry 
music and speech to our homes celebrated its fourth 
anniversary only two weeks ago. 

And yet in this brief space (1) millions on millions 
have been entertained with the very best the artist 
has to offer; (2) a singer has been heard around the 
world; (3) and our President has addressed his fellow 
Americans as a single audience. 

When onto the boundless range of audible radio 
is grafted the world-wide appeal of the picture, - 
the ideal means of entertainment would seem to have 
been attained, for the picture is without language, 
literacy or age limitation. 

By radio we shall see what is happening in a distant 
place; inaugural ceremonies, football, baseball or polo 
games; flower festival, mardi gras, or baby parade. 

So when the development of radio as a service to 
the eye has progressed to a like extent with ear- 
service radio, we will bring the entire opera to your 
home in both acting and music, or even the Olympic 
games from across the sea. 

It has been most satisfying to have had a part in 
the development of this wonderful medium of con- 
tact between individuals and between nations. My 
part being principally visual_radio, I expect great 
things from Radio Vision. 


130 


And did you ever notice the curious fact that a 
great laboratory, despite its inestimable contribu- 
tions to science and engineering, has never yet brought 
forth a great, revolutionary invention which has sub- 
sequently started a new industry, like the telegraph, 
telephone, and telescope; motion picture, typecasting 
and talking machines; typewriter, bicycle and loco- 
motive; automobile, flying machine, and radio vision. 

It has always been a poor man to first see these 
things, and as a rule the bigger the vision the poorer 
the man. 

And, do you know, that is right comforting, too; 
for I sometimes think that perhaps I myself may yet 
do something worth while if I only stay poor enough, 
long enough. 


131 


129,971 
235,469 
571,463 
653,881 
660,199 
714,577 
725,140 
841,387 
867,877 
879,532 
884,110 
929,930 
934,969 
968,484 
980,356 
980,357 
980,358 
980,359 
1,015,881 
1,030,240 
1,059,763 
1,069,535 
1,097,871 
1,135,624 
1,141,850 
1,161,734 
1,316,967 
IRA y Al titers: 
1,356,763 
1,370,504 
Psa 20 


Radio Patents of Interest 


Loomis 
Bell 
Thompson 
Pollack 
Pollack 
Gruhn 
Roberts 
DeForest 
DeForest 
DeForest 
stone-Cabot 
Latour 
DeForest 
Kruh 
Squire 
Squire 
squire 
squire 
Fessenden 
Hoglund 
Reisz 
DeBernochi 
Murphy 
Rosing 
Stille 
Rosing 
Moore 
Voulgre 
Hartley 
Hammond 
Jenkins 


1,390,445 
1,406,445 
1,413,333 
1,423,737 
1,434,064 
1,436,676 
1,440,466 
1,444,605 
1,450,080 
1,454,532 
1,467,988 
1,470,696 
1,475,583 
1,484,648 
1,485,773 
1,489,228 
1,505,158 
1,521,188 
1,521,189 
1,521,190 
1,521,191 
1,521,192 
1,521,205 
1,522,305 
1,525,548 
1,525,549 
1,525,550 
1,525,551 
1,525,552 
1,525,553 
1,530,463 


Jenkins 
Culver 
Jenkins 
sandell 
Montielhet 
Peterson 
Jenkins 
Heising 
Hazeltine 
Beatty 
Hoxie 
Nicholson 
Hoxie 
Jenkins 
Espenshied 
Hazeltine 
Martin 
Jenkins 
Jenkins 
Jenkins 
Jenkins 
Jenkins 
Stephenson 
Latour 
Jenkins 
Jenkins 
Jenkins 
Jenkins 
Jenkins 
Jenkins 
Jenkins 


Note: As Washington is 
the birthplace of radio, and 
has been the birthplace of 
more revolutionary inven- 
tions, upon which great in- 
dustries have been built, 
than any other ten-mile terri- 
tory, it may be interesting, 
and appropriate, to add here 
a recount by Mr. Jenkins of 
Washington’s claims to in- 
tellectual stimulus.—EpIrTor. 


Washington, the City of 


Enchantment 
Broadcast from WCAP, September 26, 1924 


C. Francis JENKINS 


ASHINGTON is the home of our Federal 

Government; but it 1s more than that—it is a 
delightful place to work, a stimulus to excellence in 
mental activity. ‘Those of us who had wandered 
about more or less aimlessly before we discovered 
Washington well understand how its genial climate 
called forth the Presidential praise of our honor guest 
from the cool, green hills of Vermont. 

Add to the delight of the climate, the charm of 
Washington’s setting, and one appreciates why, 
from the Executive Mansion outward to the very 
rim of federal activity, all remain, if they can, after 
leaving office. Woodrow Wilson stayed here until 
he passed away. President Harding was hurrying 

133 


home when his end came. ‘The only living ex-presi- 
dent resides in the District. 

Abraham Lincoln was loath to leave Washington, 
it is said, and so preferred a summer cottage in the 
Soldier’s Home Grounds, as did many of his succes- 
sors, rather than a more elaborate executive resi- 
dence elsewhere, while the White House was getting 
its annual dressing. 

In the house now occupied by the Cosmos Club, 
Dolly Madison ruled social Washington in such a 
scintillating setting that even the widows of presi- 
dents, with few exceptions, have made their later 
homes here. 

Nor is it strange, for this is the city the unequaled 
plan of which was worked out with such loving care 
by Major Charles L’Enfant, as he leaned over a 
drawing board in his home near the old Tudor Man- 
sion; the parks of the plan later beautified by the 
landscape gardener, Andrew J. Downing. 

And this magnificent dream city had the proper 
antecedents, too, for it was from this very site the 
old Indian chief Powhatan ruled his own vast terri- 
tory before ever the white man had set up the capital 
of a nation dedicated to peace and opportunity. 

Many eminent statesmen and great orators have 
found Washington environs so satisfying that they 
have spent their last years within this forest-like 
city. The inimitable Henry Clay was buried here 
in 1852; Elbridge Gerry, a signer of the Declaration 
of Independence, lies in the Congressional Cemetery ; 
and John Lee Carroll, a former Governor of Maryland, 
found his last resting place in a local graveyard. 

It was in Washington as the head of the Federal 
Party that that distinguished orator, Daniel Webster, 
made his indelible impress on American history. 

In the old “Union Tavern”’ on a site now occupied 

134 


by a large apartment building one could have 
found hobnobbing with resident genius, in that 
early yesterday, such guests as Louis Phillipe, Count 
Valney, Lord Lyons, Baron Humboldt, Charles 
Talleyrand, Jerome Bonaparte, Washington Irving, 
Charles Dickens, General St. Clair, Lorenzo Dow, 
John Randolph, and perhaps Charles Goodyear, 
when he was asking for a patent for vulcanizing 
- rubber. 

Even the dashing Robert E. Lee, leaving his an- 
cestral home overlooking Washington, rode regret- 
fully away to duty in his beloved south. 

One may perhaps concede that associations would 
attract retired admirals and generals to a residence 
here—Admirals Evans, Dewey, Schley, Sampson, 
Peary, and Generals Greely, Crook, Wheeler, Miles 
and Pershing, within my own unprompted memory, 
but what is the secret which brings back to Washing- 
ton those who have looked upon the enchanting spots 
of our wonderful country; the three Johns, for ex- 
ample, John C. Freemont, the great northwest path- 
finder; John W. Powell, explorer of the Grand 
Canon of the Colorado; John A. Sutter, discoverer of 
gold in California. 

Even Governor Shepherd, who made Washington, 
and afterward was practically banished to Mexico, 
prayed that he might be brought back to the city of 
his dreams, and his wish gratified, he lies at rest 
amid the grassy slopes of Rock Creek Cemetery. 

It was ever thus; even stubborn old Davy Burns 
must have thought well of Washington for he brought 
from his native land not only a charming daughter — 
but the bricks with which he builded a cottage for 
her, and from whose humble door this Scottish 
lassie later went to a haughty family and a mansion 
as the wife of Major General Van Ness. 

B30 


Not only from official life, but from all fields of 
activity, the capital city attracts to itself an unusual 
aggregation of mentality—scientific and literary and 
industrial. | 

Poets and great writers, noted scientists and re- 
nowned inventors have done their best work in the 
invigorating atmosphere of the capital, washed clear 
by the mist of the Great Falls of the Potomac. 

It was here Francis Scott Key lived when he- 
wrote ‘‘The Star Spangled Banner,’ a spot marked 
by the new memorial bridge just completed; here 
Harriet Beecher Stowe wrote that immortal story, 
“Uncle Tom’s Cabin’; Walt Whitman the first edi- 
tion of his “Leaves of Grass’; James =Brycems aes 
American Commonwealth’”’; and Owen Meredith his 
Pluciess: 

In a rose-covered cottage on the heights overlook- 
ing the river, across from the Arlington National 
Cemetery, Mrs. E. D. E. N. Southworth wrought; 
and in a less flowery abode impecunious Edgar Allan 
Poe wrote much of his “spooky stuff.” 

Looking down upon the city from the east, John 
Howard Payne, in tranquil contentment, on his 
return from a sojourn in a foreign land, wrote the 
one song which will never die, ‘‘Home, Sweet Home.”’ 

In isolated serenity in Rock Creek Park stands the 
cabin of Joaquin Miller, “‘the poet of the Sierras,” 
now the shrine of the artist as well as the writer. 

Across Lafayette Park, opposite the White House, 
George Bancroft, the great historian, calmly laid 
down his pen in his 91st year and passed to his great 
reward. ) 

And it was here that the painter James McNeill 
Whistler began his climb to an artistic, world-re- 
nowned fame. 

As for science, why Washington is the scientific 


136 


center of the world. More revolutionary discoveries 
which have been the foundations of great industries 
have been made in the District of Columbia than 
any other ten miles square in all the world. 

It was here that the great Joseph Henry spent the 
most prolific period of his sixty years of usefulness. 

On the bosom of Rock Creek, Fulton first floated 
the model of his steamboat, the Clermont; and on the 
Potomac River, Professor Langley tested out the 
aerodynamic principles upon which all airplanes are 
built, and at a time when the ‘‘flying machine’? was 
a subject not mentioned in elite scientific circles. 

In the observatory on Cathedral Heights, that 
great astronomer, Simon Newcomb, worked; and 
nearby Cleveland Abbe, the famous meteorologist, 
published the first daily weather reports. 

Between Washington and Baltimore, Professor 
». F. B. Morse, in 1844, put his telegraph to work, 
the first telegraph operator being Theodore N. Vail, 
Peemiredcent of the A. T. &.T. Company. Dr. 
Graham Bell perfected his telephone here, Professor 
Tainter the wax cylinder phonograph, and Mr. 
Berliner the talking machine. 

Both the typecasting machines, the linotype and 
monotype, were invented in the District; and here 
a stenographer in the Life Saving Service invented 
the first motion picture machine, the prototype of 
the projector used in every picture theatre the world 
over to this very day. 

From the hills of Virginia, across the river, the first 
wireless message ever transmitted was sent into 
Washington; and from Washington to Philadelphia 
the first photographs by radio were sent. 

When the Daughters of the American Revolution 
sought a permanent home no place could successfully 
compete with the charm of Washington; and here 

137 


also the American Red Cross and the Pan American 
Union set up their respective domiciles. 

In Kendall Green Park, in the northeast section 
of the city, the Columbia Institute for the Deaf was 
set up, the only Institution of its kind in the world, 
the gift of Gallaudet to the afflicted. 

It was in Washington that another philanthropist, 
William W. Corcoran, built the Louise Home for 
Southern gentlewomen, as well as the Corcoran Art 
Gallery, the latter a gift to the city. He was laid 
away in Oak Hill Cemetery, the resting place of an 
unequaled gathering of distinguished Americans. 

In the north of the city is the Walter Reed Hos- 
pital, named in honor of Dr. Walter Reed, who 
heroically risked his life to prove that yellow fever 
germs were communicated by mosquitos. 

The Carnegie Institute “for the encouragement of 
investigation, research and discovery,’ and the 
Carnegie Geophysical Laboratory are both located 
here. 

In Washington the Geographic Society was estab- 
lished, and the unique Geographic Magazine is pub- 
lished; and here the beautiful home for the National 
Academy of Science has just been dedicated. 

So the atmosphere of Washington works its 
witchery on resident as well as those who stop here 
but briefly, a mental stimulus of no uncertain 
potency; and as for scenic beauty, it is unequaled 
and getting more beautiful and more attractive all 
the time. 

As I fly above the city its streets are hidden under 
a criss-cross of green trees, with the superb white 
dome of the Capitol standing out above the verdure 
in majestic splendor; and over to the west the Lincoln 
Memorial, looking for all the world like a jewel box 
of alabaster. And on the rim of the mist beyond 

138 


stands a bowl-like marble amphitheatre keeping 
watch over the grave of the Unknown Soldier, while 
still farther around to the north looms the great 
National Cathedral on Mount St. Albans, where lies 
“the man of peace.”’ 

And it was this inspiring sight that greeted the 
homeward bound, round-the-world flyers as they 
glided over the city to a landing in Bolling Field. 

An annual pilgrimage to this mecca of glorious 
past and wondrous present, with its wealth of white 
buildings, its miles of park roads, its spring cherry 
blossoms and autumn colors is always inspiring. 

From whatever point of view, Washington well 
deserves the pride of possession of all worthy 
Americans. 


139 


Every normal man instinctively seeks a recrea- 
tional activity—hunting, fishing, riding, tennis, 
golf. The author’s relaxation from research work 
is flying an airplane—and it’s delightful sport. 


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